W4168: Environmental and Genetic Determinants of Seed Quality and Performance

(Multistate Research Project)

Status: Active

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SAES-422 Reports

Annual/Termination Reports:

[12/12/2019] [12/15/2021] [12/13/2022] [12/05/2023]

Date of Annual Report: 12/12/2019

Report Information

Annual Meeting Dates: 10/10/2019 - 10/13/2019
Period the Report Covers: 10/01/2018 - 09/30/2019

Participants

Meeting minutes attached.

Participants Attachment:

Minutes_W4168_Lexington_2019.docx

Brief Summary of Minutes

Accomplishments

Our W3168 Project that ended in 2019 had the following Objectives: <ol> <li>Identifying key factors involved in the enhancement or loss of seed quality.</li> <li>Eliminating seed dormancy as a constraint during seed production and germination in agronomic seed production and ecological/biomass seed establishment.</li> <li>Enhancing seed vigor and germination in agronomic and other species for improved stand establishment.</li> </ol>   Our W4168 Project that started in 2019 has the following Objectives: <ol> <li>Understand how developmental and environmental mechanisms affect seed quality.</li> <li>Capitalize on new technologies to assess and manipulate traits to enhance seed quality.</li> </ol>   Research Objectives for each station and group shown below (W3168/W4168): AZ, Ramin Yadegari (1/1) FL, Hector Perez (1, 3/1, 2) IA, Susana Goggi (Iowa State U.) KY, Bruce Downie (1, 3/1) KY, Robert Geneve (2, 3/2) NY, Alan Taylor (3/2) OR, Sabry Elias (1/1) SD, Xingyou Gu (1, 2/1) TX, Daniel Leskovar (3/2) VA, Gregory Welbaum (3/2)   AZ (Yadegari) Research was focused on analysis of the regulatory mechanisms that control accumulation of storage proteins and starch during mid to late stages of endosperm development in maize (Zea mays). Development of the cereal endosperm involves cell differentiation processes that enable nutrient uptake from the maternal plant, accumulation of storage products and their utilization during germination. We have used the Opaque-2 (O2) bZIP transcription-factor protein and its downstream network involved in regulation of storage protein gene expression in maize. During this period of our studies, we focused on dissecting the temporal sequence of gene activation and repression events in both wild-type and o2 mutant endosperm in maize inbred line B73 using RNA-Seq. Our data indicates multiple transitions in gene expression programs, some coinciding with previously known developmental transitions and some that may identify novel switches in temporal development of maize endosperm. We plan to further characterize the nature of gene functions associated with these gene sets.   FL (Perez) We identified environmental parameters that clarify the germination niche for seeds of a federally listed endangered plant (Linum arenicola) in collaboration with partners from Fairchild Tropical Botanic Garden. We also uncovered differential viability and vigor loss patterns of mass separated Rudbeckia mollis seeds in response to storage conditions (e.g. climate-controlled vs. non-climate-controlled systems) and aging stress imposed by the combination of high temperature and relative humidity. Subsequently, we discovered similar seasonal dormancy cycling across all R. mollis seed mass fractions. Rudebckia mollis seeds of greater mass may also possess a competitive advantage over seeds of smaller mass in defending against pathogen attack during burial in the soil profile. We related this advantage to relatively thicker seed coats in seeds of larger mass. However, the seed coat pathogen defense system seems to reflect a trade-off with defense against aging stress such that more rapid viability loss due to physiological mechanisms is evident in larger compared to smaller seeds. We partnered with a local wildflower seed producer to obtain seeds of Rudbeckia mollis and plan to share research results with the Florida Wildflower Foundation. Outputs and Short-term Outcomes: Data from our research on Linum arenciola was incorporated into the Conservation Action Plan for this species. Conservation Action Plans outline management activities for the recovery of endangered species. Our observations regarding Rudbeckia mollis highlight the importance of distinguishing between pre-sowing storage and post-storage vigour effects when quantifying relative levels of viability loss among seeds of different mass. Additionally, this work can shed more light on seed persistence dynamics in the soil. The work on R. mollis has implications for understanding potential shifts in population demographics and dynamics for seeds in general. Likewise, information generated from our work on Uniola paniculata is useful to manage germplasm and enhance seed production methods for this economically and ecologically important dune building species. We presented our research at one international and one regional meeting. Activities: We carried out lab-based research including: germination chamber screenings at various seasonal temperatures and lighting regimes, thermo-gradient table experiments, accelerated aging experiments, microscopy (i.e. optical and electron), stress-based dose response experiments, respirometry, and multi-spectral scanning. Field research consisted of implementing burial-retrieval-germination studies and in situ germination phenology experiments. Milestones: We plan to submit: 1) 1-2 articles related to L. arenicola research by 30-Mar-2020; 2) 2 articles on R. mollis work by 06-Dec-2019 and 30-Mar-2020; and 3) 1-2 manuscripts related to work on U. paniculata by 31-Aug-2020.   KY (Downie) Short-term Outcomes: There are none. As strictly basic research there is no means by which anyone will be able to make a profit from this work, use it to start a business, or otherwise identify a tangible accumulation of wealth or food from it. Similarly it will not immediately help the environment. Those operating seed banks will understand that the proteins of the translational apparatus are the most important of the proteome to protect from damage if the seed is to remain viable. However, understanding this is the case will not assist them in preserving these proteins from damage any more than is inherent in the seed’s current protection and repair mechanism. Outputs: The primary output from these endeavors are the ideas that they generate and the demonstrations of how important aspect of the protective mechanism (Raffinose Family Oligosaccharides, LATE EMBRYOGENESIS ABUNDANT PROTEINs; LEAP) are to long term seed viability. Activities: Dr. Lynnette Dirk and Dr. Bruce Downie engaged in cloning LEAP coding sequences into bacterial vectors, expressing these and purifying the recombinant proteins. These were used by the team, including a high school student, to robotically assess LEAP binding to Arabidopsis seed proteins displayed on virus coat proteins, assembling the Client Proteins (CP) for each of the LEAPs we expressed of the 51 LEAPs present in Arabidopsis thaliana. Using an Illumina sequencing technique (Paired-End Phage Sequencing; PEPSeq) tags were generated from the phage sub-libraries that constituted the  LEAP:CP repertoire. An affiliated team of bioinformaticians in Brazil are using this information to develop the Paired End Phage Explorer pipeline (PEPE). This will finally unveil the CPs associated with a specific Arabidopsis LEAP and its Soybean (Glycine max) orthologous LEAP. Other endeavors include using HPLC to explore maize (Zea mays), rice (Oryza sativa), and Arabidopsis mutants and over-expressing lines compromised in or ectopically expressing various enzymes and transcription factors influencing soluble saccharide quantities and qualities in the various seeds of the plants mentioned above. These efforts will continue in the next year of this project. Milestones: Complete the final biological replication of feeding various saccharide solutions to developing maize kernels using intravenous lines. Assess the resulting kernels for disrupted sugar quantities and qualities using HPLC. Develop the transgenic, over-expressing, Arabidopsis lines of the various LEAPs for which we have detailed CP information from Phage display and assess them, along with their insertional mutants for phenotypes relative to wild type seeds/plants. Continue to consult with the Brazilian team on improvements to and working out bugs in PEPE.   KY (Geneve) Intended activities: The research focused on determining the basic germination parameters for industrial hemp (Cannabis sativa). This included information related to temperature and the development of a seed priming protocol. Outcomes: Cardinal temperatures for industrial hemp were determined for several accessions utilizing a thermogradient table. A thermal time model was developed that determined that optimal germination occurred between 17 and 25oC. Protocols for osmotic- and solid matrix-seed priming were developed utilizing three seed accessions. Seed priming improved germination and stand establishment under greenhouse and field conditions. Outputs: Results from these studies were communicated to hemp growers at the University of Kentucky 2019 Hemp Field Day. This field day had over 500 grower participants. A formal presentation was made to seedling transplant producers at the 2019 International Plant Propagator’s Society – Eastern region annual meeting in Madison, Wisconsin regarding “Opportunities in Commercial Hemp Production”. A journal manuscript “Temperature Limits for Seed Germination in Industrial Hemp (Cannabis sativa L.)” was submitted to Seed Science Research.   NY (Taylor) A novel delivery method for the application of bio-based biostimulants as seed coatings was developed using different sources of liquid and powder forms of vermicompost and soy flour. Micronized vermicompost (MVC) and soy flour (SF) were mixed in different combinations as dry seed coating blends and applied using rotary pan seed coating equipment. The physical properties of coated seeds were measured, and as binder concentration increased, coating strength increased. The rates and percentages of germination of these coating formulations of SF+MVC did not decrease the germination parameters and were not significantly different than the control. However, the SF, SF with concentrated vermicompost extract, and SF + MVC from dairy manure increased the seedling vigor index by 24, 30, and 39 percent, respectively, compared to the control. Plant biometric parameters and nitrogen uptake per plant were also significantly higher for SF and SF+MVC coated seeds than the control, in a greenhouse environment. This is the first seed coating study to show an enhancement of plant growth with vermicompost, and vermicompost in combination with a plant-based protein that serves as a dry seed coating binder and biostimulant, respectively. Seed coatings developed in this study can serve as a model for development of the delivery systems of seeds for the application of bio-based biostimulants to enhance early plant growth.   OR (Elias) The objectives of this study were to: 1) examine the extent of dormancy in freshly harvested seeds and develop a method to break it, 2) measure the effect of having seeds with different ages in the same plant on the quality of harvested seeds, and 3) determine the suitable tests to measure seed viability and vigor. Two varieties with different seed sizes were included in the study. The quality of seeds harvested from the upper 2/3 part of the plant (mature seeds) and from the lower 1/3 part (under developed seeds) were compared. The length of dormancy in freshly harvested seeds was measured. Both varieties had a short-lived dormancy (30-45 days). Pre-chilling treatment (10°C for 5d) was effective in breaking dormancy. The difference in seed size between the two varieties did not impact seed quality. Seeds harvested from the upper part of the plant had higher quality than those from the lower part of the plant.  Seeds from the lower part of the plant need to stay an extra 7-8 days on the mother plant to reach similar quality to the upper part.  Tetrazolium, standard germination, and accelerated aging tests were suitable for measuring seed quality. These findings can increase hemp yield by 1/3 if harvest is delayed 7d. The current practice in most production systems is to harvest only the upper 2/3 of the plants.   SD (Gu) Our research was focused on seed dormancy and soil seedbank longevity. A new project was funded by USDA-NIFA Foundational Program to identify interactional partners, target genes, and the pre-harvest sprouting resistance of SD12s, a multi-genic quantitative trait locus (QTL) for seed dormancy in rice. A series of molecular biology experimental systems were developed, and candidate partners or downstream genes were screened for further confirmation. Hybridization between SD12’s isogenic lines (donors) and male sterility maintaining or restoration lines (recipients) were made to introduce the dormancy gene(s) into the recipient background by marker-assisted backcrossing. The other project was newly funded by USDA-NIFA BRAG Program to evaluate effects of seed dormancy genes on soil seedbank longevity (SL) and to identify new SL QTL and their G×E interactions in till and no-till cropping systems. Four seed dormancy genes, including their combinations, were all involved in regulation of SL in the soil; and the data were published. A population of 450 recombinant inbred lines (RILs) in the F12 generation were purified and propagated; seed samples are being used to evaluate for SL in the soil of a rice field. In addition, a new project was initiated to elucidate epigenetic mechanisms of seed dormancy using a model system developed from weedy rice. Five graduate students and three postdoc/visiting scientists were received training in the above-stated projects.   TX (Leskovar) Intended activities: The research for this year focused on two projects: 1. Determine how selective organic media containing humic substances impact transplant quality traits and reduce transplant sock of high value vegetable species growing under drought and heat stress conditions, and 2. Determine best grafted tomato combinations (scion/rootstock) based on yield and quality stability across diverse environments in Texas.  Outcomes: Using lignite-based humic substances (HS) applied to a peat-growth medium, the study evaluated seedling growth responses of four vegetable species each with two different cultivars: pepper (bell- and jalapeno-type), tomato (round- and cherry-type), watermelon (seeded 2x, and seedless 3x), and lettuce (Romaine- and Bibb-type).  Once seedlings traits were measured in the nursery, transplants from each crop/cultivar were field transplanted under drought (vs. well-watered) and heat (vs. cool temperatures) conditions. Overall, HS-treated transplants had: 1) increased leaf and root biomass after transplanting due to faster growth rate compared to control; 2) lower root/shoot ratio before transplanting, but higher after 10 days; 3) increased root length and surface area. Yield increases due to HS depended on crop and environmental conditions: bell-pepper under drought and heat stresses; round- and cherry-tomato under well-watered and cool season (no stress); triploid-watermelon under well-watered and hot season; romaine-lettuce under heat stress. In the tomato grafting project, the team identified grafted tomato combinations (scion/rootstock) with high stability for yields and yield components across diverse environments in Texas. Grafted plants consistently increased marketable yields by 5 to 69%. Outputs: Results from these two studies were communicated to growers at the Uvalde May 2019 Vegetable Field Day, which was attended by +80 participants. Participants also took a hands-on tomato grafting workshop class, which was complemented with an educational seminar highlighting the science behind grafting. The event was covered by AgriLife Today and other regional outlets <a href="https://agrilifetoday.tamu.edu/2019/05/14/vegetable-wheat-field-day-at-texas-am-agrilife-center-in-uvalde-draws-producerinterest/">https://agrilifetoday.tamu.edu/2019/05/14/vegetable-wheat-field-day-at-texas-am-agrilife-center-in-uvalde-draws-producerinterest/</a>  Findings were also presented and discussed in seven oral presentations at the: annual meetings of the American Society of Horticultural Sciences (Las Vegas, NV); Grafting Symposium, International Society of Horticultural Sciences (Charlotte, NC); vegetable field days; and annual ASA-Agronomy Society graduate student field day (San Antonio, TX). Two manuscripts were published from previous work, one chapter book on ‘Transplanting’ is in press in the 2nd edition of the Vegetable Physiology book, two were submitted to Acta Horticulturae, and three related to 2019   projects are about to be submitted to peer reviewed Journals.   VA (Welbaum) We now know that tobacco mosaic virus can be transmitted to the next generation of plants by both by seed coat transmission and embryo transmission. Using plastic tunnels for vegetable production can increase the water use efficiency of certain crops. Wild tobacco plants can be infected with the cucurbit disease, bacterial fruit blotch, enabling easier study of the pathogen/plant genetic interactions that are responsible for infection. During the past year, four masters-degree students and one Ph.D. student have been trained and received degrees from this research.

Publications

Campbell-Martinez, G., M. Thetford, D. Miller and H.E. Pérez. 2019. Seedling emergence of Lupinus diffusus in response to abrasion in an electric seed scarifier. Native Plants Journal. 20:14-24.   Han Q., Qi J., Hao G., Zhang C., Wang C., Dirk L.M.A., Downie A.B., Zhao T. 2019. ZmDREB1A regulates RAFFINOSE SYNTHASE controlling raffinose accumulation and vegetative chilling stress tolerance in maize. Plant and Cell Physiology. doi:10.1093/pcp/pcz200   AL-Amery M., Downie B., DeBolt S., Crocker M., Urschel K., Goff B., Teets N., Gollihue J., Hildebrand D. 2019. Proximate composition of enhanced DGAT high oil, high protein soybeans. Biocatalysis and Agricultural Biotechnology. 21: 101303.   Gu L, Jiang T, Zhang C, Li X, Wang C, Zhang Y, Li T, Dirk L, Downie B, Zhao T. 2019. Maize HSFA2 and HSBP2 interact with each other and antagonistically modulate raffinose biosynthesis and plant abiotic stress tolerance. The Plant Journal. TPJ-00441-2019. doi: 10.1111/tpj.14434   Zhang Y, Sun Q, Zhang C, Hao G, Wang C, Dirk LMA, Downie AB, Zhao TY. 2019. Maize VIVIPAROUS1 interacts with ABA INSENSITIVE5 to regulate GALACTINOL SYNTHASE2 expression controlling seed raffinose accumulation. Journal of Agricultural and Food Chemistry. 67: 4214-4223.   Lynnette M. A. Dirk, and A. Bruce Downie. 2018. An examination of Job’s rule: Protection and repair of the proteins of the translational apparatus in seeds. Seed Science Research. 28, 168–181. https://doi.org/10.1017/S0960258518000284.   Lynnette M.A. Dirk, Manoj Majee, Santosh Kumar, A. Bruce Downie. 2018. PHYTOCHROME INTERACTING FACTOR1 interactions leading to the completion or prolongation of seed germination. Plant Signaling and Behavior. 13(10):e1525999 DOI: 10.1080/15592324.2018.1525999.   Manoj Majee, Santosh Kumar, Praveen Kumar Kathare, Shuiqin Wu, Derek Gingerich, Nihar R Nayak, Louai Salaita, Randy Dinkins, Kathleen Martin, Michael Goodin, Lynnette M.A. Dirk, Taylor D. Lloyd, Ling Zhu, Joseph Chappell, Art G. Hunt, Richard Vierstra, Enamul Huq, and A. Bruce Downie. 2018. KELCH F-BOX Protein Positively Influences Seed Germination by Targeting PHYTOCHROME-INTERACTING FACTOR1. Proceedings of the National Academy of Science U.S.A. 115 (17) E4120-E4129.   Wilson, S.B., R.L. Geneve and F.T. Davies, Jr. 2018. An online study tool for reviewing plant propagation terms and concepts. HortTechnology 28:851-854. <a href="https://doi.org/10.21273/HORTTECH04184-18">https://doi.org/10.21273/HORTTECH04184-18</a>     AL-Amery, M., Geneve, R.L., M.F. Sanches, P.R. Armstrong, E.B. Maghirang, C. Lee, R.D. Vieira, and D.F. Hildebrand. 2018. Near-infrared spectroscopy used to predict seed germination and vigour in soybean seed lots. Seed Science Research 1–8   <a href="https://doi.org/10.1017/S0960258518000119">https://doi.org/10.1017/S0960258518000119</a>   Geneve, R.L. and S.T. Kester. 2018. Morphophysiological dormancy in Heptacodium. Seed Science Research 1-5 <a href="https://doi.org/10.1017/S0960258518000053">https://doi.org/10.1017/S0960258518000053</a>   Geneve, R.L., C.C. Baskin, J.M. Baskin, K.M.G. Jayasuriya, and N.S. Gama-Arachchige. 2018. Functional morpho-anatomy of water gap complexes in physically dormant seed. Seed Science Research 1-6 <a href="https://doi.org/10.1017/S0960258518000089">https://doi.org/10.1017/S0960258518000089</a>   Davies, F. T. Jr., R. L. Geneve and S. B. Wilson. 2018.  Hartmann and Kester’s Plant Propagation:  Principles and Practices.  Boston: Prentice-Hall.  Ninth edition.   Amirkhani, M., Mayton, H.S., Netravali, A.N. and Taylor, A.G. 2019. A Seed Coating Delivery System for Bio-Based Biostimulants to Enhance Plant Growth. Sustainability  11, 5304. <a href="https://doi.org/10.3390/su11195304">https://doi.org/10.3390/su11195304</a>   Huang, W. and A.G. Taylor. 2019. Water uptake, respiration and germination of eastern gamagrass seeds as influences by mechanical seed treatments: Unlocking mechanisms of seed dormancy. Seed Science and Technology, 47, 2, 1-15. <a href="https://doi.org/10.15258/sst.2019.47.2.06">https://doi.org/10.15258/sst.2019.47.2.06</a> Pipatpongpinyo, W., U. Korkmaz, H. Wu, A. Kena, H. Ye, J. Feng, and X.-Y. Gu. 2019. Assembling seed dormancy genes into a system identified their effects on seedbank longevity in weedy rice. Heredity. (doi.org/10.1038/s41437-019-0253-8).   Macias-Leon, M. A. and D.I. Leskovar. 2019. Containerized onion transplant: Management systems to enhance growth, yield and quality. HortScience 54:60-69.  <a href="https://doi.org/10.21273/HORTSCI13438-18">https://doi.org/10.21273/HORTSCI13438-18</a>   Othman, Y.A. and D. I. Leskovar. 2019. Nitrogen management influenced root length intensity of young olive trees. Scientia Horticulturae 246, 726-733. <a href="https://doi.org/10.1016/j.scienta.2018.11.052">https://doi.org/10.1016/j.scienta.2018.11.052</a>   Leskovar, D.I. and Othman. 2019. Nitrogen management for improving root and shoot components of young 'Arbequina' olives.  HortScience 54:175-180. <a href="https://doi.org/10.21273/HORTSCI13397-18">https://doi.org/10.21273/HORTSCI13397-18</a>   Agehara, S. and D.I. Leskovar. 2018. Optimizing spray application rates of abscisic acid for height control of jalapeño transplants. Acta Hortic. 1204, 235-242 DOI: 10.17660/ActaHortic.2018.1204.31 <a href="https://doi.org/10.17660/ActaHortic.2018.1204.31">https://doi.org/10.17660/ActaHortic.2018.1204.31</a>   Leskovar, D.I. and Othman, Y. 2018. Efficacy of 1-methylcyclopropene in promoting shoot growth of tomato transplants. Acta Hortic. 1204, 229-234 DOI: 10.17660/ActaHortic.2018.1204.30 <a href="https://doi.org/10.17660/ActaHortic.2018.1204.30">https://doi.org/10.17660/ActaHortic.2018.1204.30</a>   Ellis, Madeleine D., Jessica M. Hoak, Bradley W. Ellis, Jessica A. Brown, Tim L. Sit, Carol A. Wilkinson, T. David Reed, and Gregory Welbaum. 2019 "Quantitative real-time PCR analysis of individual flue-cured tobacco seeds and seedlings reveals seed transmission of Tobacco mosaic virus." Phytopathology DOI: 10.1094/PHYTO-06-19-0201-FI.   Traore, S.M., Eckshtain?Levi, N., Miao, J., Castro Sparks, A., Wang, Z., Wang, K., Li, Q., Burdman, S., Walcott, R., Welbaum, G.E. and Zhao, B., 2019. Nicotiana species as surrogate host for studying the pathogenicity of Acidovorax citrulli, the causal agent of bacterial fruit blotch of cucurbits. Molecular Plant Pathology. 20: 800–814.   Acharya, T.P., Welbaum, G.E. and Arancibia, R.A., 2019. Low Tunnels Reduce Irrigation Water Needs and Increase Growth, Yield, and Water-use Efficiency in Brussels Sprouts Production. HortScience. 54: 470-475.

Impact Statements

VA (Welbaum) A new book on vegetable seed biology, technology, and production is in preparation by authors Welbaum and Bradford. The book will help train a new generation of workers for the vegetable seed industry. Scanning technology is being applied seeds to detect and removed those infected by Bacterial Fruit Blotch (BFB) disease. Developing biological control measures to prevent BFB disease in the field is another goal of this project.

Date of Annual Report: 12/15/2021

Report Information

Annual Meeting Dates: 10/14/2021 - 10/17/2021
Period the Report Covers: 10/01/2020 - 09/30/2021

Participants

Radegari, Ramin (yadegari@arizona.edu) - The Univ. of Arizona;
Perez, Perez (heperez@ufl.edu) - Univ. of Florida;
Goggi, Susana (susana@iastate.edu) - Iowa State Univ;
Mirsa, Manjit (mkmisra@iastate.edu) - Iowa State Univ;
Kawashima, Tomo (tomo.k@uky.edu) - Univ. of Kentucky;
Isaacs, Krista (isaacskr@msu.edu) - Michigan State Univ.;
Torrion, Jessica (jessica.torrion@montana.edu) - Montana State Univ.;
Taylor, Alan (agt1@cornell.edu) - Cornell Univ.;
Nault, Brian (ban6@cornell.edu) - Cornell Univ.;
Jiang, Yu (yj522@cornell.edu) - Cornell Univ.;
Sosnowskie, Lynn (lms438@cornell.edu) - Cornell Univ.;
Elias, Sabry (sabry.elias@oregonstate.edu) - Oregon State Univ.;
Gu, Xingyou (Xingyou.Gu@sdstate.edu) - South Dakota State Univ.;
Latvis, Maribeth (Maribeth.Latvis@sdstate.edu)- South Dakota State Univ.;
Leskovar, Daniel (d-leskovar@tamu.edu) - Texas A & M Univ.;
Welbaum, Greg (welbaum@vt.edu) - Virginia Tech. Univ.;

Brief Summary of Minutes

W4168 Multi-Research Project Meeting, Cornell Agri-Tech, Cornell University, Geneva NY (Oct 15-16, 2021)

Friday (Oct. 15, 2021)

A number of Cornell Agri-Tech staff assisted the safety, technological needs, and educational tours of the meeting. Below were the presenters and state representatives of this project.

By 8:58 A.M., Dr. Elias opened the meeting, welcomed the participants in-person and via virtual connectivity, and thanked Dr. Taylor and Cornell administrators for hosting the meeting. A short introduction by the participants followed.

Dr. Taylor introduced Cornell administrators leading to their respective presentations. Dr. Jan Nyrop (Director, Cornell AgriTech/NY State Agricultural Experiment Station) summarized AgriTech’s research strengths, facilities, and overall function. Dr. Margaret Smith (Associate Dean and Director of Cornell Ag Experiment Station) described the NY agriculture, forestry, natural resources, and tourism interrelated functions. Also, summarized Cornell’s land grant mission, facilities, operations, research, and extension. Dr. Chris Smart (Director of School and Integrated Plant Science) described the integration of several departments into one school. Dr. Smart pointed out the importance of this multistate research group and highly regarded the significance of seed health – healthier and quality seed leads to a healthier plant. Dr. Brian Nault (Program Leader of Entomology) described the breadth and depth of the entomology program at Cornell, highlighted the collaborative seed treatment project with Dr. Taylor, and highlighted the Cornell-initiated seed treatment products for horticultural crops.

After the Cornell administrators' introductions, it was then opened for discussion. Dr. Mirsa (Director of Seed Science Center in Iowa) applauded the Cornell administrators and addressed the challenge of seed biology effort locally and upward-looking, globally, and into the future. Finally, he also pointed out that Dr. Taylor’s research position should continue after retirement.

State report highlights:

Hector Perez (Univ. of Florida): Detailed the environmental factors that enhance seed quality and integrity of natural habitats of native species for restoration projects. Under the forest environment, seeds remained dormant, which was much more pronounced at warmer temperatures than in the other environments. In addition, the maternal environment played a strong influence on germination.

Greg Welbaum (Virginia Tech): Summarized research on germination with salinity stress and lower water potential, determining the degree of infection of fruit blotch disease to the pericarp or the embryo, and poor soy-edamame germination performance compared with the typical soybean seed.

Brian Nault (Cornell Univ.): Presented onion maggot management with seed treatment, tremendous insect pressure, there is less room for spatial rotation, and producers are left with the use of insecticides. Producers are facing a new challenge with the banning of chlorpyrifos active ingredient. A collaborative project with Alan Taylor identified a new active ingredient for seed treatment to improve the control of onion maggot.

Jessica Torrion (MT State Univ.): Presented spring wheat near-isoline genes in the presence and absence of high protein gene and their contrasting environments directly related to senescence, spike maturation, and seed alpha-amylase activity. Mentioned colleague Justin Vetch in Montana, who found an allele regulating preharvest sprout.

Krista Isaacs (Michigan State University): Presented seed systems approach, significant issues in seed systems, and specific studies internationally that lead to improved end-use quality and adoption. Highlighted women participation in the seed systems approach in selecting seed traits.

Daniel Leskovar (Texas A & M University): Presented transplant stress adaptation and stand establishment. Low levels of N reduced shoot growth in tomato, pepper, and lettuce. More vigorous transplants performed better under abiotic stress. Under biostimulants, Novihum produced the most vigorous plant and higher yield. Wildtype rootstock performed better under drought stress. Biomolecules, growth regulators, carbon-based media, and spectral lights blends can modulate the root system for better adaptation to stress.

Sabry Elias (Oregon State Univ.): Evaluated the effect of x-ray energy of the electromagnetic spectrum on seed quality for pear and peach seeds. Shelled seeds, typically, have better germination. But when applied with x-ray on the shorter duration of exposure, it had a positive effect on germination for both whole and shelled seeds, but when prolonging the exposure, it had significantly low germination. A fortuitous extra day of chilling seeds improved germination significantly. Overall, seed x-ray exposure and exposure time were not the factor affecting vigor or viability but rather due to deep dormancy.

Tomo Kawashima (Univ. of Kentucky): Demonstrated an inward movement of seed central cell F-actin filament. The duration of the liquid endosperm phase correlates with the final seed size. F-actin dynamic alteration in the liquid endosperm alters Arabidopsis's endosperm and final seed size. In soybean, the final seed size varied with environment during the grain-filling period, and research is ongoing.

Xingyou Gu (South Dakota. State Univ.): Pointed seed dormancy regulatory genes in agriculture application. Seed dormancy genes regulate soil seed bank longevity. The degree of dormancy correlated with plant height. Slr1 gene enhanced the degree of primary seed dormancy, whereas the Gid-1 gene reduced the degree and duration of dormancy.

Ramin Yadegari (Univ. of Arizona): Summarized drought stress impact on maize early development. There is a differential gene expression at the early stage of development even with only a couple of days of water stress duration. Sets of gene networks are expressed in well-watered and suppressed under water-stressed and vice versa.

Susana Goggi (Iowa State. Univ): Seed size of corn and planting depth in cool-season perennial grass. A detailed experiment was conducted in precise seed sizing the seed materials to determine the impact of seed size on germination performance. In the end, seed size was not a factor in germination but more so in seeding depth.

Maribeth Lativus (Iowa State Univ.): Smoke-induced germination considering the northern great plain smoke incidences. Smoke treatment-induced, inhibited, or no effect with germination. Induced or inhibition is scattered in the phylogenic pattern, and the majority of the species were not impacted by smoke. Ancestral reconstruction suggested that species that respond to smoke on some of these species is a recent response mechanism.

Alan Taylor (Cornell University): Summarized recent seed technology projects and in particular, on hemp seed science and technology. Also, contrasted the performance of water as a carrier versus dry powder coating. All seed biological enhancements tested were ineffective.

Business Meeting:

At 3:05 John Erickson, USDA National Program Leader (Physiology of Agricultural Plants), summarized USDA-NIFA priorities and focal points of the various programs. Discussed the AFRI Foundational Program, education and workforce development, and sustainable agricultural systems. Also highlighted panelists recruitment in NIFA to increase participation and diversity in the panel.

Elias opened the business meeting, approving the previous minutes of the meeting (motioned by Taylor, second by Torrion). Then, Elias solicited the need to continue the meeting on Saturday with the group.

Discussion on other events other than education tours. The Saturday discussion will include planning or collaborative interactions such as the next 5-year renewal. The group agreed to meet 9:00 A.M. the following day (Goggi, Taylor, Gu, Perez, Elias).

Discussion on reporting. Torrion solicits accomplishments and impact statements in layman’s term and broad by Nov. 15, 2021, to allow enough time to consolidate the group report 60 days after this meeting. It was also highlighted that there are changes in procedures and processes in NIFA and providing reports online. Ramin coordinates with Torrion in the reporting (Elias, Welbaum, Torrion, Yadegari, Taylor).

Discussion on the 2022 meeting location. Iowa was proposed venue in coincidence with the word food prize event, South Dakota, or Arizona. Yadegari will host the 2022 meeting in Arizona. The meeting will also have an emphasis on the planning and rewriting of the groups proposal (Leskovar, Torrion, Goggi, Yadegari, Gu).

Lastly, Leskovar emphasized the importance of seed specialists in each of the land grant universities and to encourage administrators for a seed biologists position or related fields with seed-focus research be refilled.

Finally, it was agreed that Welbaum is the 2022 Chair, Torrion as Vice-Chair, and Perez as the Secretary.

The group toured Taylor’s Seed Science and Technology lab, followed by a tour of the USDA plant genetics resource center by Zach Stansell.

Saturday (Oct. 16, 2021). Taylor opened the business meeting at 9:05 A.M.

Discussion on the group's website and other informational materials. The group website to include the research, mission, and members is vital. Also, this information shall be added to the NIMS website. These should help revive memberships, as it has been declining. Regular updating helps educate the public, including the industry, and not just the participating members. For example, new members had a hard time navigating this group's information and memberships. It was also raised that the challenge was to maintain the platform; however, it was also discussed the most challenging one is more of content than the platform itself as there are members who are IT savvy in the group. Kawashima agreed to be the focal person for the web development and hosting in coordination with Torrion and Yadegari to include the mission, goals, videos, photos, impacts, and membership directory. (Taylor, Elias, Torrion, Welbaum, Gu, Kawashima, Perez, Issacs)

There was a discussion on ongoing challenges on seed quality. Gu addressed that there are still problems associated with several issues in seed dormancy, breeding, preharvest sprout, germination.

Finally, the challenge on collaborative projects was emphasized considering the diversity of research priorities within the group. The difficulty is acknowledged in seed science, but accessibility of information and expertise is much more important. This group is a significant resource, and that a continued seed science expert is essential in each agricultural university, just like what was stated in Bredford’s letter. It was encouraged to use that letter to encourage administrators to continue seed science research or programs.

Accomplishments

Objectives: <ol> <li>Understand how developmental and environmental mechanisms affect seed quality.</li> <li>Capitalize on new technologies to assess and manipulate traits to enhance seed quality.</li> </ol>  Research objectives for each of the participants: AZ, Ramin Yadegari (1) FL, Hector Perez (1) IA, Susana Goggi (1) KY, Bruce Downie (1) KY, Robert Geneve (1,2) KY, Tomo Kawashima (1) MT, Jessica Torrion (1) NY, Alan Taylor (2) OR, Sabry Elias (1,2) SD, Maribeth Latvis (1) SD, Xingyou Gu (1, 2) TX, Daniel Leskovar (1) VA, Gregory Welbaum (2)   AZ (Yadegari) Research was focused on understanding how endosperm development in maize (Zea mays) is affected by drought stress after fertilization. Cereal endosperm mediates uptake of sugars and metabolites and synthesizes massive amounts of storage proteins and starch to support the developing embryo and the germinating seedling. As such, cereal endosperm is of enormous importance to the economy because it constitutes a major portion of human caloric intake directly or indirectly. Endosperm development involves cell proliferation and differentiation processes that are sensitive to environmental stresses including drought and heat. Although we understand the major processes that are affected with the vegetative structure of plants in response to such stresses, very little is known about the effect of stresses on endosperm development specifically. We have analyzed the structure of the maize endosperm and the genes expressed within the whole kernel upon varying lengths of water withdrawal one day after pollination. We parsed the gene expression programs in well-watered and drought-stressed kernels into networks that can identify the responses of the various compartments within the kernel, including the endosperm to varying periods of drought stress imposed on the whole plant. These data can provide clues as to the nature of endogenous biological processes that are dysregulated within the seed to respond to drought.  FL (Perez) We uncovered the influence of different natural maternal environments, collection years, and maternal environment × collection year interactions on the seed quality of Harperocallis flava (Harper’s Beauty). Moreover, we identified that a portion of H. flava seeds possess morphological dormancy while remaining seeds possess morpho-physiological dormancy and the environmental conditions required to overcome such dormancy mechanisms. Also, since H. flava is a globally imperiled species, it was important to discern the ability of seeds to persist in the soil and remain viable under various seed storage conditions. We found that seeds from a specific maternal environment displayed lower seed quality than seeds collected from two other environments. Likewise, significant drought across the maternal environments contributed to decreased seed quality in 2020 compared to seeds collected in 2018 and 2019. Maternal environments and collection years interacted significantly depending on the temperatures used to test germination. Our burial-retrieval-germination experiments revealed that H. flava seeds can form short-term persistent seeds banks. The reciprocal burial treatments also point to significant seed lot and burial site effects on subsequent seed survival and germination capacity. Finally, our seed desiccation and storage experiments suggest that H. flava seeds are tolerant of considerable desiccation but sensitive to freezing and sub-freezing temperatures. Therefore, H. flava seeds may express an intermediate storage physiology and alternative methods of seed storage, such as cryopreservation, may be required to conserve seeds of this endangered species.  IA (Goggi) Abiotic and biotic stress during vegetative and reproductive stages of plant development can detrimentally affect seed quality and composition. These seed quality changes can affect seedling emergence in the field, especially under a stressful environment of a perennial ground cover. The goal of the proposed research is to investigate the fundamental mechanisms for seed quality changes environmental stresses can produce and their effect on seed and seedling emergence in the field. Plants grown in growth chambers, greenhouses and filed environments were artificially or naturally stressed. Better understanding of seed quality characteristics that affect seedling emergence under different environments. Research findings are shared with the scientific community and general public through peer-reviewed publication and stakeholders virtual and in-person workshop and short courses  KY (Downie) Using the seed as a paradigm a consortium of researchers at the University of Kentucky and University of Louisville launched a project in August, 2021 to introduce LATE EMBRYOGENESIS ABUNDANT PROTEINs (LEAPs) and nonreducing sugars (NRSs) into Drosophila melanogaster embryos to permit their partial desiccation and cryopreservation. This collaboration was a new linkage established among three faculty outside of the W4168 group with a W4168 member (Downie). Instrumentation were procured in January 2021 to allow LEAP:Client Protein (CP) interactions to be validated and quantified in solution. Knowledge gained using the instrument was presented to the Tri-Society meeting, Salt Lake City, UT, Monday, November 8th, 2021. Developed the transgenic, over-expressing, Arabidopsis lines of the various LEAPs for which we have detailed CP information from Phage display and over-expressing lines for the client proteins CASC3 and ABI3. We are now assessing them, along with their insertional mutants, for phenotypes relative to wild type seeds/plants.  KY (Geneve) Studies were conducted to reduce or bypass the stratification requirement for dormancy release and germination in grape seed. By utilizing fresh seed from mature fruit that had not completed the final maturation drying stage of development was found to be induced to germinate after a 2000 ppm gibberellic acid treatment or after clipping the distal end of the seed. This effect was further enhanced by combining the gibberellin and clipping treatments yielding germination and seedling development comparable to traditional stratification treatments.  KY (Kawashima) Plant fertilization is the initiation of seed development. Plant fertility is critical not only for plants themselves, for their survival, but also for us as seeds provide more than 70% of our calories. Using Arabidopsis thaliana as a model, we have identified that plant gametes utilize novel pathways to control dynamic fertilization processes such as sperm nuclear migration. The endosperm, which is a tissue that supports embryo development within a seed, is known to control the final seed size. However, the molecular mechanisms by which the endosperm contributes to the final seed’s size remains largely unknown. Using soybean as a crop model, we investigated how a temperature shift during endosperm development affects subsequent seed development as well as the final seed size. We found that the period when the endosperm is rapidly developing is more sensitive to temperature change than the rest of the seed development periods. MT (Torrion) We subjected eight near-isoline (NIL) wheat pairs of in the presence or absence of high grain protein gene (Gpc-B1) trait to rainfed and irrigated environments. High grain protein spring wheat tends to lose green pigments (senesce) earlier than in wheat where Gpc-B1 gene is absent. Our research goal was to associate senescence rate to seed amylase activity late in the season that breaks down starch into sugar (via falling number test). The occurrence of physiological maturity in wheat was not correlated with the falling number test – a test that qualitatively assess amylase activity. However, the wheat lines interacted with the environment on the falling number test. We identified three NIL pairs with generally low falling number, and even lowered falling number with irrigation. The germination test of our study confirmed no significance among the genetic lines.     NY (Taylor) The purpose of this research was to collect efficacy data on biological, biochemical, and chemical fungicide seed treatments on hemp (Cannabis sativa L.) to mitigate damping-off and to enhance stand establishment in the field. This was a multi-state project, and seed treatments were evaluated in the field in New York (NY), North Dakota (ND), and Virginia (VA) and at two planting dates in each state in 2020. A single seed lot of a dual-purpose (fiber + grain) cultivar (‘Anka’) was treated using a laboratory-scale rotary pan coater.  Five biological treatments consisting of array of diverse microorganisms, two biochemical treatments, and four chemical treatments were tested. A bioassay with naturally infested soil was used to assess preliminary activity of seed treatments for inhibition of germination and protection against damping-off. There were no significant differences in the occurrence of abnormal or normal seed germination for any treatment when compared to the non-treated control in the laboratory assay. The biochemical seed treatment SafeGuardTM (active ingredient; organic copper) performed as well as the chemical treatments Apron XL® + Maxim® 4FS and Mertect® 340F in preventing damping off whereas, the biological treatments did not differ from the non-treated control in terms of disease incidence.. In general, biological seed treatments did not improve plant stands in the field. Biochemical seed treatments Prudent 44 ® with Nutrol ® (active ingredient; phosphite) and SafeGuardTM along with chemical seed treatments had acceptable efficacy and improved stand establishment when compared to the non-treated control across field locations. Based on efficacy results from laboratory and field trials the copper seed treatment has potential for both conventional and organic commercial applications for hemp field production. OR (Elias) In 2020/2021, Dr. Hiro Nonogaki and his group studied the evolutionary drivers of the seed maturation regulators DELAY OF GERMINATION1 family genes. Dr. Thomas Chastain and his group studied the genetic variation for seed retention in accessions and genotypic of perennial ryegrass; and the effect of mowing and growth regulators on fine fescue. Dr. Sabry Elias and his group studied issues on seed quality and dormancy in hemp; and the effect of x-ray on seed quality of pear and peach.  Some grants and commodity groups supported those projects.  Several practical applications and recommendations to growers have been generated from our research projects.  Numerous multistate activities involved stakeholders and seed industry, as well as conference presentations have been done. A number of papers have been published on these subjects. SD (Latvis) In collaboration with Drs. Lora Perkins and Josh Leffler through the SDState Native Plant Initative, we assessed the phylogenetic signal in smoke-inducted germination for 350 species of North American seeds. We created a phylogeny for all species used in controlled smoke experiments, plotted response data (i.e. survival analyses for germination) on the phylogeny, assessed phylogenetic signal, and conducted Ancestral State Reconstruction of this response. Results suggest that smoke-induced germination is an evolutionary labile trait, with no clear phylogenetic pattern, nor correlation with EPA ecoregion. These results were presented at the Botanical Society of America 2021 meeting.  Following the BSA meeting, we met with collaborators (Dr. Matt Johnson and Yanni Chen at Texas Tech U) who are interested in scaling up this project for a global synthesis of this trait. SD (Gu) On the ecological genomics of seed bank longevity in rice, two sets of experiments were continued to estimate effects of seed dormancy (SD) genes on soil seed bank longevity or to identify quantitative trait loci (QTL) associated with soil seed bank longevity in weedy rice. Seed samples from a set of isogenic lines (ILs) for nine genotypes of the SD7-1/Rc and SD4/Pb loci, or from a population of 450 recombinant inbred lines (RILs) were buried in the top (2 cm) and deep (20 cm) soil in a rice field for 7 or 8 months to mimic no-till and till practices, respectively. Data from the ILs revealed that both SD7-1/Rc and SD4/Pb contributed the variation in seed bank longevity through their main (additive and dominance) and epistatic effects and genotype-by-environment interactions. The SD7-1/Rc and SD4/Pb genes from weedy red rice encode the basic-helix-loop-helix family transcription factors and have pleiotropic effects on seed dormancy and red/purple pericarp colors. The new data indicated that the two pleiotropic genes are also involved in the regulation of seed longevity. Data from the RIL population demonstrated genotypic (G), burial environment (E) and G-by-E interactional effects on soil seed bank longevity under the field condition. A high-resolution linkage map was constructed based on a subpopulation of 250 RILs, which were genotyped with a 7K SNP array. On the regulatory mechanisms of seed dormancy in rice, three sets of experiments were continued or conducted to elucidate developmental mechanisms of seed dormancy. The first set of experiments aimed to identify genes regulated by SD12s (SD12a, b and c). Five sets of transcriptomes were obtained from 10-d embryos of developing seeds from the isogenic lines for SD12a, SD12b, SD12c, SD12a&b, and SD12a,b&c, respectively. The transcriptomes were used to infer genes commonly regulated by all SD12s or specifically regulated by individual SD12s. The common or specifically regulated genes were annotated for temporal expression patterns during seed development and will be used to infer gene regulatory networks for the development of embryo dormancy. The second set of experiments were continued to introduce SD12s into the genetic background of cultivars to improve their resistance to pre-harvest sprouting. About 10 F2 populations grown on and harvested from Missouri Rice Research Farm are being evaluated for seed dormancy and genotyped for marker-assisted selection. And the third set of experiments was conducted to determine if the gibberellin (GA) signaling genes are involved in the development of seed dormancy. TX (Leskovar) We conducted three studies: 1) determining the potential of plant biostimulants to enhance early growth and yield in pepper and tomato when applied as a pre-transplant treatment in the rooting media, 2) determining the effects of humic substances on hydroponically grown leafy greens when applied in a recirculating closed system, and 3) investigating the role of rootstocks on the growth and physiology of grafted tomato transplants. The first two studies evolved from discussions with stakeholders (nurseries, biostimulant manufacturers, growers) who collectively identified the need to determine the impacts of selected biostimulants to mitigate early transplanting stress and improve growth and final yield of selected vegetable crops. The third study expands our previous efforts related to screening rootstocks and varieties of fresh market tomato under major abiotic stresses (drought and heat) in Texas. In study 1, we found that partial destructive harvests of transplants revealed early growth differences between treatments in seedling height, leaf number, and stem diameter in both cultivars. Multiple harvests of ripe fruits throughout the growing season showed final yields were similar between treatments in 'Mama Mia Giallo' but humic acid-treated 'Tenor' outperformed other treatments. In study 2, our initial analysis of data from two lettuce cultivars showed strong cultivar dependent responses. 'Green Forest' lettuce showed no significant responses to humic substance supplementations, but 'Tropicana' lettuce showed higher °Brix, stem thickness, and fresh weight yield responses to humic substance supplementation. In study 3, from the screening of tomato cultivars grown in open conventional vs. organic field, we have determined that yield performance was significantly influenced by grafting. Other studies are showing grafting with ‘Maxifort’ rootstocks improved root antioxidant enzyme content in response to high temperatures. Additional work showed that grafting with wild relative rootstocks enhanced tomato drought tolerance without increasing amino acid contents when compared to non-grafted and commercial rootstock-grafted plants. Findings from these studies are intended to provide recommendations to small-scale growers to enhance their profits and contribute to the sustainable production of high value vegetable crops. VA (Welbaum) 1. Two MS, Kale Mueller and Christos Galanopoulos, and one Ph.D. student, Merve Kiremit, completed degrees under my direction studying seed production quality of cantaloupe, enhancing field emergence, and disease transmission of melon, respectively, 2. FTIR (Fourier transform infrared) spectroscopy and X-ray analysis allows embryos of seeds infected with Acidovorax citrulli to be nondestructively detected and removed from commercial seed lots, 3. we discovered and effective natural seed treatment that can kill the significant worldwide disease Acidovorax citrulli in culture and on artificially inoculated seeds, 4. we demonstrated the potential of virus induced gene silencing as a tool for studying gene for gene pathogenicity/resistance of bacterial fruit blotch disease, 5. we discovered that low tunnels with water-filled thermal tubes heated by resistive heating strips powered by solar panels could significantly improve the rate of emergence of summer squash and kale in a field study, 6. the invasive grass, Arthraxon hispidus, successfully colonized new areas because of a sprawling growth habit, prolific seed production, fast germination without dormancy  allowing it to gain a competitive advantage over other species, 7. the optimal temperature range for edamame seedling emergence is 25-32 ℃, which is lower than grain-type soybean cultivars (29-36 ℃), 8. soybean did not emerge at around 4 ℃, however, edamame seeds may have higher tolerance to low temperatures compared with grain-type soybean, and 9. edamame needed more thermal time to emerge which may be a seed quality issue.

Publications

Nguyen, C.D., Chen, J., Clark, D., Pérez, H. and H. Huo. 2021. Effects of maternal environment on seed germination and seedling vigor of Petunia x hybrida under different abiotic stresses. Plants 10(3): 581. DOI: <a href="https://doi.org/10.3390/plants10030581">https://doi.org/10.3390/plants10030581</a>.  Genna, N.G. and H.E. Pérez. 2021. Intra-population seed survival during burial on a mass basis. Flora 274: 151756. DOI: <a href="https://doi.org/10.1016/j.flora.2020.151756">https://doi.org/10.1016/j.flora.2020.151756</a>. Genna, N.G., Walters, C., Pérez, H.E. 2020. Viability and vigour loss during storage of Rudbeckia mollis seeds having different mass: an intra-specific perspective. Seed Science Research 30(2), 122-132. doi:10.1017/S09602585200001. Pérez, H. and Chumana, L. 2020. Enhancing conservation of a globally imperiled rockland herb (Linum arenicola) through assessments of seed functional traits and multi-dimensional germination niche breadths. Plants 9(11): 1493. <a href="https://doi.org/10.3390/plants9111493">https://doi.org/10.3390/plants9111493</a>. Pérez, H.E., Hill, L.M., Walters, C. 2020. A protective role for accumulated dry matter reserves in seeds during desiccation: Implications for conservation. pp. 133-142. in: Chong, P.A., Newman, D.J., Steinmacher, D.A. (eds) Agricultural, Forestry and Bioindustry Biotechnology and Biodiscovery. Springer. Dean, Ashley N., Katharina Wigg, Everton V. Zambiazzi, Erik J. Christian, A. S. Goggi, Aaron Schwarte, Jeremy Johnson and Edgar Cabrera. 2021. Migration of Oil Bodies in Embryo Cells during Acquisition of Desiccation Tolerance in Chemically Defoliated Corn (Zea mays L.) Seed Production Fields. In: Modern Seed Technology, Special Issue, Ed. A. Taylor. Agriculture 11(2), 129. <a href="https://doi.org/10.3390/agriculture11020129">https://doi.org/10.3390/agriculture11020129</a> Chad Kimmelshue, A. S. Goggi and Rebecca Cademartiri. 2019. Biological control coatings based on bacteriophages and polymers against bacteria in seeds. Scientific Reports 9, Article 17950 (2019). <a href="https://doi.org/10.1038/s41598-019-54068-3">https://doi.org/10.1038/s41598-019-54068-3</a> Moore, K. J., R. P. Anex, A. E. Elobeid, S. Fei, C. B. Flora, A. S. Goggi, K. L. Jacobs, A. L. Kaleita, P. Jha, D. A. Laird, D.s L. Karlen, A. W. Lenssen, T. Lübberstedt, M. D. McDaniel, D. R. Raman, S. L. Weyers. 2019. Regenerating agricultural landscapes with perennial groundcover for intensive crop production. Agronomy 9(8), 458. <a href="https://doi.org/10.3390/agronomy9080458">https://doi.org/10.3390/agronomy9080458</a> Zhang, Yumin, Li, Dan, Dirk, Lynnette M. A., Downie, A. Bruce, Zhao, Tianyong. 2021. ZmAGA1 Hydrolyzes RFOs Late during the Lag Phase of Seed Germination, Shifting Sugar Metabolism toward Seed Germination Over Seed Aging Tolerance. J. Agric. Food Chem. 69: 11606−11615. <a href="https://doi">doi</a>: 10.1021/acs.jafc.1c03677. Zhang, Yumin; Zhen, Sihan; Zhang, Chunxia; Shangguan, Xiaoqing; Lu, Jiawen; Bao, Runhao; Dirk, Lynnette; Downie, A. Bruce; Wang, Guoying; Zhao, Tianyong; Fu, Junjie. 2021. Regulatory network reveals causality of ZmCT2 on oil amount through embryo size modulation. Under Peer review for consideration in The Plant Journal. Raihan, T., Geneve, R., Perry, S., and Rodríguez López, C. M. (2021) The regulation of plant vegetative phase transition and rejuvenation: miRNAs, a key regulator. Epigenomes 5:24; <a href="https://doi.org/10.3390/epigenomes5040024">https://doi.org/10.3390/epigenomes5040024</a> Bolt, B., Magnani, R., Nosarzewski, M., Rodríguez López, C. and Geneve, R. (2021) Gibberellin and clipping promote germination in fresh grape seeds. Combined Proceedings International Plant Propagators’ Society 70: in press. Chiluwal A, Kawashima T, Salmeron M. Soybean weight responds to increase in assimilate supply during late seed-fill. (2021) Journal of Crop Improvement <a href="https://doi.org/10.1080/15427528.2021.1943732">https://doi.org/10.1080/15427528.2021.1943732</a> Sharma V, Clark AJ, Kawashima T. Insights into the molecular evolution of fertilization mechanism in land plants. (2021) Plant Reproduction <a href="https://doi.org/10.1007/s00497-021-00414-3">https://doi.org/10.1007/s00497-021-00414-3</a> Ali MF and Kawashima T. Formins control dynamics of F-actin in the central cell of Arabidopsis thaliana. (2021) Plant Signaling & Behavior <a href="https://doi.org/10.1080/15592324.2021.1920192">https://doi.org/10.1080/15592324.2021.1920192</a> Ali MF, Fatema U, Peng X, Hacker SW, Maruyama D, Sun MX, Kawashima T. ARP2/3-independent WAVE/SCAR pathway and class XI myosin control sperm nuclear migration in flowering plants. (2020) Proceedings of the National Academy of Sciences of the U.S.A. 117:32757-32763 https://doi.org/10.1073/pnas.2015550117 Shin JM, Yuan L, Ohme-Takagi M, Kawashima T. Cellular dynamics of double fertilization and early embryogenesis in flowering plants. (2020) JEZ-B Molecular and Developmental Evolution <a href="https://doi.org/10.1002/jez.b.22981">https://doi.org/10.1002/jez.b.22981</a> Ohnishi Y and Kawashima T. Plasmogamic paternal contributions to early zygotic development in flowering plants. Frontiers in Plant Science 11:871 (2020) <a href="https://doi.org/10.3389/fpls.2020.00871">https://doi.org/10.3389/fpls.2020.00871</a> Mi, R.; Taylor, A.G.; Smart, L.B.; Mattson, N.S. Developing Production Guidelines for Baby Leaf Hemp (Cannabis sativa L.) as an Edible Salad Green: Cultivar, Sowing Density and Seed Size. Agriculture 2020, 10, 617. <a href="https://doi.org/10.3390/agriculture10120617">https://doi.org/10.3390/agriculture10120617</a> Tang, X., Hao F., Yuan, H., Yan, X., Yang, D., Taylor, A. G. 2020. Uptake and translocation of imidacloprid via seed pathway and root pathway during early seedling growth of corn. Pest Management Science. <a href="https://doi.org/10.1002/ps.5930">https://doi.org/10.1002/ps.5930</a> Wang, Z., Amirkhani, M., Avelar, S.A., Yang, D., Taylor, A.G. 2020. Systemic uptake of fluorescent tracers by soybean (Glycine max (L.) Merr.) seed and seedlings. Agriculture 10, 248. <a href="https://doi.org/10.3390/agriculture10060248">https://doi.org/10.3390/agriculture10060248</a> McDonald MR, Vander Kooi K and AG Taylor. 2020. Evaluation of various insecticides for control of maggots in yellow cooking onions, 2019. Muck Vegetable Cultivar Trials & Research Report No. 69. p 58-59. McDonald MR, Vander Kooi K and AG Taylor. 2020. A comparison of film coat and pelleted application methods for control of maggots in yellow cooking onions, 2019. Muck Vegetable Cultivar Trials & Research Report No. 69. p 62-63. McDonald MR, Vander Kooi K and AG Taylor. 2020. Evaluation of various fungicides for control of onion smut in yellow cooking onions, 2019. Muck Vegetable Cultivar Trials & Research Report No. 69. p 66-67. Taylor, A.G. Seed storage, germination, quality and enhancements. 2020. In The Physiology of Vegetable Crops. 2nd edition. Ed: H.C. Wien and H. Stutzel. CAB International: Wallingford, England; pp 1-30. Nishiyama E, Nonogaki M, Yamazaki S, Nonogaki H, Ohshima K. 2021. Ancient and recent gene duplications as evolutionary drivers of the seed maturation regulators DELAY OF GERMINATION1 family genes. New Phytologist 230, 889-901 Tubbs, T.B., and T.G. Chastain. 2020. Genetic variation for seed retention in accessions and genotypic of perennial ryegrass. Seed Prod. Res., Oregon State Univ. Ext/CrS 164. 17-20. Anderson, N.P., B.C. Donovan, C.L. Garbacik, and T.G. Chastain. 2020. Spring mowing and plant growth regulator effects on first and second year fine fescue seed crops. Seed Prod. Res., Oregon State Univ. Ext/CrS 164. 21-25. <a href="https://digitalcommons.murraystate.edu/do/search/?q=author_lname%3A%22Elias%22%20author_fname%3A%22Sabry%22&start=0&context=7364626">Elias, S.G., Y.C. Wu, and D.C. Stimpson. 2020.  </a> <a href="https://digitalcommons.murraystate.edu/cgi/viewcontent.cgi?article=1017&context=jahr">Seed Quality and Dormancy of Hemp (Cannabis sativa L.)</a>. <a href="https://digitalcommons.murraystate.edu/jahr">J. Ag. Hemp Res.</a> <a href="https://digitalcommons.murraystate.edu/jahr/vol2"> 2</a> (1): 1-15. Angsumalee, D., S.G. Elias, N. P. Anderson, T.G. Chastain, and C.J. Garbacik. 2019. Plant growth regulator and irrigation effects on physiological and harvest maturity of red clover in relation to seed quality. Agron. J. vol. 3 (2): 1-9. Gu, X.-Y. Seed dormancy genes and their associated adaptive traits underlie weed persistence: A case study of weedy rice. In: Persistence Strategies of Weeds in Agriculture (1st edition). Eds. Upadhyaya, M.K., Clements D.R., and Shrestha A. John Wiley and Sons Ltd | Wiley-Blackwell. (In Press; ISBN9781119525608)  Macías-León, M.A. and D.I. Leskovar. 2020. Tray seedling density and transplanting date impacted onion yield and bulb size. Acta Hortic. 1273, 377-386 <a href="https://doi.org/10.17660/ActaHortic.2020.1273.49">https://doi.org/10.17660/ActaHortic.2020.1273.49</a> Tahat, M.M, Alananbeh, K.M., Othman, Y., and D. Leskovar. 2020. Soil health and sustainable agriculture. Sustainability 2020, 12(12), 4859; <a href="https://doi.org/10.3390/su12124859">https://doi.org/10.3390/su12124859</a> Alves, FM, Joshi, M, Djidonou, D, Joshi, V, Gomes, NI and DI Leskovar. P<a href="https://scholar.google.com/citations?view_op=view_citation&hl=en&user=4TvoAfcAAAAJ&sortby=pubdate&citation_for_view=4TvoAfcAAAAJ:2tRrZ1ZAMYUC">hysiological and biochemical responses of tomato plants grafted onto solanum pennellii and solanum peruvianum under water-deficit conditions</a> Plants 2021, 10(11),  2236; <a href="https://doi.org/10.3390/plants10112236">https://doi.org/10.3390/plants10112236</a> <h4>Joshi, M, Leskovar, D, Djidonou, D, Jifon, J, Avila, C, Masabni, J and K Crosby. Production systems and growing environments had stronger effects than grafting on the nutritional quality of tomato. ACS Food Science & Technology 2021 1 (8), 1399-1411 DOI: 10.1021/acsfoodscitech.1c00051</h4> Bhattarai, S.; Harvey, J.T.; Djidonou, D.; Leskovar, D.I. 2021. Exploring morpho-physiological variation for heat stress tolerance in tomato. Plants 2021, 10, 347. <a href="https://doi.org/10.3390/plants10020347">https://doi.org/10.3390/plants10020347</a>                                                                                                                                                Leskovar, D.I.; Othman, Y.A. Direct seeding and transplanting influence root dynamics, morpho-physiology, yield, and head quality of globe artichoke. Plants 2021, 10, 899. <a href="https://doi.org/10.3390/plants10050899">https://doi.org/10.3390/plants10050899</a> Early growth and photosynthetic responses of pepper to changing temperature treatments. D Djidonou, DI Leskovar; 2021 ASHS Annual Conference. Harvey, J.T. and D.I. Leskovar. Yield and quality responses of hydroponic lettuce to supplemental led red: blue light ratios. 2020 ASHS Annual Conference. Qin, K. and DI Leskovar. Humic substances improved vegetable seedling quality and post-transplant yield performance under stress conditions. 2020 ASHS Annual Conference. Cambell, C.A., Leskovar, D.I., and F.M. Alferez. Panel Discussion: Challenges and opportunities in abiotic stress control using plant growth regulators. 2020 ASHS Annual Conference. Leskovar, D. Multistate Regional Project: Researcher Spotlight. June 16, 2020 <a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__nam01.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Fwww.youtube.com-252Fwatch-253Fv-253D6E-2D4QxLtjCY-26data-3D02-257C01-257Csara.delheimer-2540colostate.edu-257C666ad0fe79e346f9a72d08d812349865-257Cafb58802ff7a4bb1ab21367ff2ecfc8b-257C0-257C0-257C637279364401384801-26sdata-3DW0bF6Qk-252BW6O50SYmQ7nYsQ2MRaFQg-252B2X1ODykt-252FnRao-253D-26reserved-3D0&d=DwMGaQ&c=r_tSStIHV2ie60z4DgB-pQ&r=rF_OPtcBsN4v2IIh7o0hik_cnaXpJ1NgKhbgPxxa0mw&m=BYfQrer86l5h0ofWU-7dRkcFkwM_j1DmS42Wy7v3KTs&s=pkMFPCUViwL_KDukiu-vSfONmeIKo8t5yDvs00W-E0I&e=">https://www.youtube.com/watch?v=6E-4QxLtjCY</a> <a href="https://agrilifetoday.tamu.edu/2020/06/16/texas-am-agrilife-involved-in-multistate-and-international-seedling-improvement-project/">https://agrilifetoday.tamu.edu/2020/06/16/texas-am-agrilife-involved-in-multistate-and-international-seedling-improvement-project/</a>  WELBAUM, G.E. and BARNEY, J.N. 2021. Sweet basil (Ocimum basilicum L.) seed mucilage: hydration, water relations, and ecology. Scientia Horticulturae (in review). LAKOBA, V., WELBAUM, G.E., SEILER, J., BARNEY, J.A.  2021. Perennial invader’s seed, but not rhizome, emergence traits correlate with climate and land use origin. NeoBiota (accepted, in press). AVERITT, B.J., WELBAUM, G.E., LI, X., PRENGER, E., QIN, J. AND ZHANG, B., 2020. Evaluating genotypes and seed treatments to increase field emergence of low phytic acid soybeans. Agriculture 10: 516-533; doi:10.3390/agriculture10110516. Mueller, K. E., Welbaum, G. E., Samtani, J., & Lavis, C. (2021). Does position in cantaloupe (Cucumis melo L.) fruit affect seed quality? Online Masters Research Project Report. Virginia Tech, Blacksburg, VA 24060, 33 pages. Merve Kiremit (2021) Detection of Acidovorax citrulli, the causal agent of bacterial fruit blotch disease of Cucurbits, prevention via seed treatments and disease resistance genes. Legumes Li, X., Welbaum G.E. Ridout S.L. Zhang B.  Vegetable soybean and its seedling emergence in the United States. In: Legumes. IntechOpen Publishing. London, UK. 21 Pages. (in processing)

Impact Statements

VA (Welbaum) 1)Acidovorax citrulli is one of the most serious seed transmitted plant diseases affecting the world today. Our research is making progress in the search for genetic resistance to this serious international disease. Detecting infected seeds and removing them from seed lots can keep the disease out of newly established production fields, 2) training seed scientist for jobs in the multibillion-dollar US seed and seed treatment industries is fundamental to maintaining US competitiveness in world agriculture, 3) controlling invasive species is a key to maintaining biological diversity in the world. Understanding how to control the invader Arthraxon hispidus, will protect habitat for native species in the mid-Atlantic, 4) vegetable soybeans are a nutritious and popular around the world but underutilized in the US. Most of the edamame currently consumed in the US are imported but could be produced here if poor emergence issues can be resolved. We are studying why edamame vegetable soybeans are harder to establish than agronomic grain soybean cultivars. Edamame seeds are larger and take longer to hydrate that grain soybean cultivars. They do not germinate well below 5 degrees C. Edamame seeds leak more electrolytes which attracts pathogens to young seedlings making the use of fungicide and certain biologicals critical for preventing seedborne disease, and 5) testing state-of-the-art seed vigor and seedling emergence platform (LabFieldTM thermogradient analysis system) developed in our lab continues. This device is being produced and sold to seed scientists and commercial seed producers around the world, so they can better assess seed viability and vigor.

Date of Annual Report: 12/13/2022

Report Information

Annual Meeting Dates: 10/13/2022 - 10/15/2022
Period the Report Covers: 10/01/2021 - 09/30/2022

Participants

University of Arizona, Ramin Yadegari
University of Florida, Hector Perez
University of Kentucky, Robert Geneve
University of Kentucky, Tomo Kawashima
Michigan State University, Margaret Fleming
Michigan State University, Krista Isaacs
Montana State University, Jessica Torrion
Cornell University, Alan Taylor
Oregon State University, Sabry Elias
South Dakota State University, Maribeth Latvis
South Dakota State University, Xingyou Gu
Texas A&M, Daniel Leskovar
Virginia Tech, Gregory Welbaum

Brief Summary of Minutes

The annual meeting was called to order at 8:30am on 14-Oct-2022. A brief discussion of plans and goals for the meeting ensued after introductions. Dr. Yadegari introduced Dr. Parker Antin (Associate Vice-President for Research (ALVSCE) & Associate Dean for Research (CALS) at the University of Arizona) for welcoming remarks. Dr. Murat Kacira then discussed activities at the Controlled Environment Agricultural Center at the importance of seed research for controlled environments. Researchers gave state reports from 10:15am until 12pm. Emmanuel Gonzalez, a Ph.D. candidate, presented on his research. State reports continued from 1:30-2:30pm.

Dr. Greg Welbaum called the business meeting to order at 2:45pm. Dr. Paul Johnson discussed national program leadership. Dr. Johnson provided advice on structure and format for the upcoming W4168 project re-write. He emphasized the use of lay language when writing impact statements and to reduce the size of project descriptions. Dr. Johnson advised a target submission date of March 2024. The group then discussed how to clarify and broaden current objectives. The group decided to edit objective 1 but leave objective 2 as is. Objective 1 will no read: “Understanding how genetic and environmental mechanisms affect seed processes”. The business meeting concluded at 3:30pm. The group then toured the Controlled Environment Agriculture Facility.

The business meeting resumed on 15-Oct-2022 starting at 8:30am. The group sought volunteers for the re-write committee. Four members agreed to serve on the committee. The group then continued a discussion of the re-write focusing on creating unifying themes such as climate change and ecology since the group membership is shifting. The group discussed recruiting new members given the upcoming wave of retirements. Members discussed the inclusion of extension and outreach activities as outputs. A suggestion was made that members of the re-write committee take on specific objectives to facilitate the process. The group was encouraged to initiate the re-write process during the fall of 2023 utilizing on-line collaboration technologies. The group committed to providing requested information in a timely manner.

Discussion then shifted to identifying a location for the 2023 meeting. The group voted to hold the 2023 meeting in Virginia. Dr. Welbaum will investigate this and report back. Discussion moved on to selecting new officers. Dr. Kawashima agreed to serve as secretary, Dr. Torrion will advance to chair, and Dr. Pérez will serve as vice-chair. Dr. Torrion then assumed leadership as new chair and called for new business. The group was reminded that annual reports are due in 60 days. Dr. Pérez agreed to send members a template that emphasized the Appendix D/SAES-422 format. A suggestion was made to initiate the re-write process during spring 2023. Members also agreed to solicit participation from seed-centric colleagues. The business meeting was then paused to complete state reports.

The business meeting resumed with the creation of a website to be used as a recruitment tool. The new website would have a more graphical format than the text rich NIMSS site. Another goal of the website is to increase visibility of seed biology research conducted across the US. Drs. Kawashima and Torrion on working on the new website. The business meeting was then adjourned.

Accomplishments

AZ (Yadegari) – Research was focused on understanding two major questions focused on how drought and mutations that alter basal endosperm transfer layer (BETL) can independently alter endosperm development and consequently the overall kernel size and quality in maize (Zea mays). We analyzed the structure of the maize endosperm and the genes expressed within the whole kernel upon varying lengths of water withdrawal one day after pollination. We have developed a dataset of the gene sets dysregulated under drought conditions. We have also generated mutant combinations in a class of transcription factor genes that are responsible for proper differentiation and function of the BETL. One of these mutant combinations showed a delayed and diminished development of BETL and a concomitant reduction in kernel size and quality. Furthermore, some of the gene sets dysregulated in the BETL mutants are highly similar to those in kernels grown under drought. These data can provide clues as to the nature of biological processes that can be dysregulated within the seed in response to both endogenous and environmental cues. FL (Pérez) – Small holder farmers in the southeastern US are expressing interest in the practice of saving farm grown seeds from open-pollinated crops that may demonstrate appropriate market demand and regional adaptability. However, adoption of this practice is constrained by a lack of technical expertise related to seed production and biological knowledge underpinning the on-plant development of high-quality seeds and maintenance of post-harvest seed quality. At the same time, natural resource practitioners in the same region struggle to obtain high-quality seeds of wild species necessary for re-vegetation and landscape rehabilitation programs. They report a lack of key information on how various land management practices and prevailing environmental conditions influence seeds quality. We worked with four small holder, local, farmer collaborators to identify three vegetable and one wildflower crop of interest. We investigated the influence of 1) crop management and seasonal timing on seed development, seed yield, and proportion of filled seeds; 2) seed source (i.e., locally produced vs. international origin) on subsequent crop traits; and 3) post-harvest seed treatments on germination capacity. Likewise, we collaborated with land managers to study how timing of prescribed burns and habitat of origin influenced seed fill, germination capacity, and vigor of wiregrass (Aristida stricta) a keystone bunchgrass of xeric and mesic pine ecosystems. We discovered that the production of high-quality vegetable and wildflower seeds is feasible despite Florida’s hot, humid climate. Season of planting is crucial. For example, farmers should plant Yukina Savoy (Brassica rapa L. subsp narinosa) in the late fall to obtain healthy, high-quality seeds by mid-spring. Planting Yukina Savoy in the late winter/early spring pushes the seed production window into late spring. However, disease pressure increases considerably at this time as daily humidity and rainfall potential increases. Similarly, cowpea (Vigna unguiculata) should be planted by mid-September rather than June or July to avoid disease pressure that influences seed quality. Production of Bellevue Butternut (Cucurbita moshata) squash seeds does not seem adversely affected by its typical production season. We found that seed development of the selected vegetable crops is consistent despite considerably different farming practices and crop management. Moreover, we were able to pinpoint optimal widows throughout the seed developmental program that contribute to maximum germination ability, minimum seed moisture content, and resistance to aging stress. Farmers were often interested in collecting seeds early during the developmental program. Nonetheless, we were able to demonstrate the negative impact of early collection on seed quality. We also determined that locally sourced seeds of Yukina Savoy produced plants with better vigor and greater biomass than plants produced from seeds of international origin after one generation of seed production in Florida. We determined that butterfly milkweed (Aslcepias tuberosa) seed yield was similar between the first and second years of seed production. This plant has the potential to produce > 200,000 seeds per hectare. Growing butterfly milkweed plants in a landscape fabric system to minimize competition from weeds did not diminish seed yields. But producers should avoid shading as this produces 1.2 to 9.6-fold decrease in seed yield depending on duration of shade exposure. Butterfly milkweed has an extended flowering season and produces fruits from June through September. Our research revealed that seed quality, in terms of germination capacity and rate, was better for seeds harvested in July or August rather than September. We also found that butterfly milkweed seeds from plants originating in north-central Florida do not require cold, dry conditions to promote germination. In fact, this often-cited recommendation was detrimental to germination. Our conversations with farmer collaborators and a formal survey of the wider farming community revealed that many farmers in the region have the intent to enter seed production but lack resources (e.g., financial, technical, informational) to do so. Some farmers also expressed concerns on post-harvest handling and storage of seeds. This makes sense in Florida’s hot, humid climate that is not conducive for seed storage especially for limited resource farmers who do not possess climate-controlled facilities for maintaining seed viability. Our farmer collaborators also indicated that they plan to continue seed production for butterfly milkweed, Bellevue butternut squash, and cowpea. One collaborator mentioned that while seed production of Yukina Savoy is feasible, they would not continue with this crop as it may not match well with their farm management plan. Nevertheless, the same farmer decided to purchase some of the desiccant based seed drying systems that we demonstrated as part of the project. We observed that habitat of origin and timing of prescribed burn were associated with the amount of seed fill for wiregrass. Seeds collected from a xeric site had the highest proportion of unfilled seeds (64%), while seeds collected from mesic sites displayed lower proportions of unfilled seeds (34-55%). Unconditioned, bulk seed lots of wiregrass sell for $140 per pound. Our economic analysis suggested that at the fill levels represented here as much as $131 out of $140 goes towards unfilled seeds when collections occur from xeric sites compared to $69 out of $140 for collections from mesic sites. We also discovered that plots burned later in the growing season (i.e., July) produced more filled seeds than plots burned earlier in the growing season (i.e., April-May). Interestingly, germination of filled seeds was relatively high (67-73%) across habitat type and burn years. Seeds responded with the highest and most rapid germination following exposure to spring temperatures. Summer and winter temperatures induced the lowest germination responses. This supports the recommendation to sow seeds in spring to facilitate plant establishment. Moreover, wiregrass seeds appear to lose vigor over a few months of lab storage. Therefore, precautions should be taken to ensure proper post-harvest handling KY (Downie, Geneve, Kawashima) – LEA14, a LATE EMBRYOGENESIS ABUNDANT PROTEIN (LEAP) of the dehydrin family was found to bind ABSCISIC ACID INSENSITVE3 (ABI3) at the B3, DNA binding domain. This interferes with ABI3 action such that seeds from lea14 are ABA hypersensitive while LEA14-OE seeds are ABA hyposensitive. ABI3 upregulates LEA14 thought the single By/Sph motif present in the LEA14 promoter while VIVIPAROUS1/ABI3-LIKE2 (VAL2), another B3 domain protein involved in epigenetic silencing downregulates LEA14 expression. LEA14 also binds VAL2 but not at the B3 domain. Dietary augmentation of the non-reducing sugar trehalose and the osmoprotective amino acid proline in Drosophila melanogaster embryos has been successful. LATE EMBRYOGENESIS ABUNDANT PROTEINs (LEAPs) and additional trehalose is being introduced through sonoporation. Additional lines of D. melanogaster have been generated that express various brine shrimp (Artemia franciscana) LEAPs. Embryos will then be assessed for their ability to withstand partial desiccation and cryopreservation. Studies were conducted to improve the germination capacity in industrial hemp. Cardinal temperatures for industrial hemp were determined for two accessions and a thermal time model was developed that modeled germination at temperatures between 17 and 25oC. In addition, parameters for seed priming were developed that could improve stand establishment of field seeded hemp. Also, a physical pericarp removal protocol was developed for improved germination in low germinating seed accessions of industrial hemp. On average, pericarp removal improved final germination in low-germinating seed lots by approximately 38% compared to intact seed germination. The endosperm within a seed is a tissue that supports embryo development and is a product of fertilization. Endosperm cells undergo nuclear divisions without cytokinesis right after fertilization, generating a large multi-nuclear cell. Cellularization subsequently occurs.The duration of this multi-nuclear endosperm phase is correlated with the final seed size. However, the molecular mechanisms and cellular dynamics by which the endosperm contributes to final seed size remains largely unknown. We have characterized nuclear divisions and movement as well as the role of the cytoskeleton in this unique endosperm development in Arabidopsis thaliana via confocal live-cell imaging technology. Separately, using soybean as a crop model, we investigated how assimilate supply changes during early seed development and how this affects subsequent seed development. We found that assimilate changes early in seed development plays a critical role in determining maximum seed weight and hence has an influence on seed quality. IA (Goggi) – Iowa researchers investigated the effects of chemical defoliation on the migration patterns of oil bodies within embryo cells during desiccation. Chemical defoliation of seed corn production fields accelerates seed maturation and desiccation and expedites seed harvest. Early seed harvest is important to minimize the risk of frost damage while in the field. Premature defoliation may interfere with the migration of oil bodies within embryo cells during desiccation and affect seed germination and vigor. This study demonstrated that oil bodies within embryo cells followed normal migration patterns according to seed moisture content, and seed quality remained high, regardless of defoliation treatment. Chemical defoliation is a viable production practice to accelerate seed corn desiccation, and to manage harvest and seed drier availability more efficiently without negatively affecting seed germination and vigor. Likewise, researchers constructed a library of images showing results of biochemical staining assays that tested for maize seed viability after drying. Researchers also explored how seed size and seed density uniformity in a bag of commercial hybrid seed affect seed germination and emergence in the stressful field conditions of a perennial ground cover. This research shed light on farmers’ misconception that variation in seedling emergence is due to disparities in seed size within a bag of seeds. Research findings demonstrated that depth of planting, rather than seed size, is the primary cause of uneven emergence and yield decline in corn. In a separate study, researchers compared and optimized the original protocol used to detect Pantoea stewartii subsp. stewartii (Pss) in maize seeds. For ground seeds, naturally and artificially contaminated samples were analyzed after purifying the seeds extract. Sensitivity and efficiency were measured by spiking the seed extracts with different levels of the bacterium. A robustness evaluation of the SYBR-PCR was realized. The evaluation included different thermocycler brands, master mix brands, and deviations in annealing temperature. Standard genomic curves of qPCR with cycle threshold (Ct) values vs. 10-fold serial dilutions of Pss strain 9239 purified genomic DNA starting with 10 ng were analyzed. Seed samples with different levels of contamination are being prepared and characterized for an inter-laboratory study. To validate the results, samples will be distributed to two seed industry laboratories and a USDA research laboratory. The team extended the applicability of this technique to detect Pss in treated maize seeds.  It will analyze and summarize the results of the inter-laboratory comparative test and submit the data for approval by the National Seed Health System (NSHS) Technical Review Panel. The group also conducted experiments to evaluate the interaction of seedling and seed pathogens with seed quality and its effect on soybean emergence and seedling vigor. Seed lots of different seed quality levels were created by accelerated-aging treatments. The effect of aging treatment (AA) on seed performance was tested in growth chambers with and without the seed-borne pathogens. Overall, low quality seeds negatively impacted germination, seedling growth, root weight and volume. A significant interaction was detected between AA treatment and Fusarium graminearum (Fg) inoculation only for root fresh weight, but the effects were not additive or synergistic at 20°C. There were few significant treatment effects at 25°C. Overall impact of Fg inoculation on emergence and seedling health was less than expected, and a heightened susceptibility of AA-treated seeds was not observed. The experiment will be repeated using additional isolates of Fusarium and Rhizoctonia. Substantial improvements have been made in developing an effective protocol for greenhouse screening of iron deficiency chlorosis and Fusarium root rot using a hydroponics system. This progress paved the way for collaboration with other Iowa State researchers. This study uses a nutrient solution that mimics more closely Iowa’s soils with iron deficiency chlorosis (IDC). MI (Fleming) – We continued collecting and analyzing data from the 16th bottle of seeds buried by Dr. William Beal in 1879. Twenty Verbascum seeds germinated, of which one was confirmed by ITS sequencing to be a hybrid of V. thapsus x blattaria, while the remainder were V. blattaria. Beal’s reports only mention V. thapsus, so the source of V. blattaria seeds remains a mystery. Tissue from one V. blattaria, plant 2021-10, was used for whole genome sequencing and assembly. The assembly is currently being refined using transcript We have recovered three intact Verbascum seeds from the germination test and have several other Verbascum seed collections available. We are planning comprehensive experiments to assess the effects of seed storage environment and duration on the germination process. These experiments will include physiological and molecular assays. MT (Torrion) – We tested sets of hard red winter wheat and soft white winter wheat market classes. The latter is not a popular class of winter wheat despite its higher yield potential compared with the former. Soft white winter wheat tends to be vulnerable to late maturity-alpha amylase activity of the seeds and in a worst-case scenario, to preharvest sprout. We tested irrigation management via surface drip tape in environment 1 such as 1) no stress (100 percent evapotranspiration, 100ET), 2) following 100ET but the final irrigation was at flower, 3) 100ET but final irrigation at milk, 4) deficit irrigation at 66% ET [66ET], and a 5) rainfed check. Environment 2 followed the same protocol as Environment 1 but with rainfall simulation within the grain-filling stage using a center pivot overhead sprinkler. We found that continuous application of irrigation beyond the flowering stage causes a lowering of falling numbers – an indicator test for increased amylase activity regardless of wheat type. Also, the continuous wetting of wheat heads via the simulated rainfall events during the grain-filling stage increased amylase activity by 10%. Reducing amylase activity, especially in soft white winter wheat, which is more vulnerable to amylase activity than hard red winter wheat, is done by terminating irrigation management at the flowering stage. For either of the market classes, continuous irrigation after flower either at 100ET or at deficit level did not improve yield or seed quality. NY (Taylor) – New tools are needed for weed management especially during the Critical Weed Free Period (CWFP) of crop development. The CWFP is the time where interspecific competition must be reduced to maximize yield production, usually the first few weeks following crop emergence. One approach is to develop imaging technologies to recognize and differentiate between crop and weed seedlings to facilitate precision weed management. Hemp (Cannabis sativa) was chosen as the model crop as weed control options, particularly herbicide availability, are limited in the US. Our approach was to use fluorescent tracers, applied as either seed or soil treatments, which are taken up by hemp seedlings. Rhodamine compounds have a desired optical property that both absorbs light and fluoresces in the visible range, so conventional illumination sources and imaging sensors can be used to excite and detect the unique fluorescence in the lab and field. A prototype fluorescence imaging system with needed algorithms and graphic user interface (GUI) was developed at Cornell AgriTech for data acquisition and analysis for lab testing. The selectivity of rhodamine, fluorescent tracers was tested in a crop/weed competition study in growth chamber studies. Rhodamine was applied as a seed treatment or soil applied at time of planting. Velvetleaf (Abutilon theorphrasti) was used as the model weed. Velvetleaf was selected for use in this study as it is a common weed throughout many hemp growing regions of the US. Velvetleaf seeds were planted 2.5 cm from the treated hemp seed. Fluorescence was detected only in the crop seedlings when rhodamine was applied as a seed treatment; conversely, some fluorescence was observed in the velvetleaf seedlings from a soil application. OR (Elias) – The seed group at Oregon State University conducted studies in both basic and applied research. The two broad objectives of the current W4168 project that we focused on are:  1) Understand how developmental and environmental mechanisms affect seed quality, and 2) Capitalize on new technologies to assess and manipulate traits to enhance seed quality. Dr. Hiro Nonogaki and his group studied seed dormancy, germination, and pre-harvest sprouting. Dr. Thomas Chastain and his group studied the effect of plant growth regulators on improving yield of grass species and other crops. Dr. Sabry Elias and his group studied seed quality, bio-enhancement, and storability in hemp; the effect of using high temperatures on the quality of coated seeds; and bioassay methods to screen winter wheat for quizalofop herbicide tolerance. Several practical applications and recommendations to growers have been generated from our research projects. Numerous multistate activities involved stakeholders and seed industry, as well as conference presentations that have been delivered. Several papers have been published or under review on these subjects. SD (Gu and Latvis) – The first set of preliminary experiments were conducted to evaluate effects of GA signaling genes on seed dormancy. All three GA signaling gene, Slr1/slr1, Gid1/gid1 and Gid2/gid2, were associated with the degree of primary seed dormancy and germination velocity in seed populations segregating for each of the loci. To determine if any of the GA signaling genes interact(s) with seed dormancy (SD) genes cloned from weedy rice, we developed three F2 populations, each containing allelic variants at the all four seed dormancy (SD) loci, SD1-2 (A/a), SD7-1 (B/b), SD7-2 (C/c), and SD12 (D/d), and the alleles at one of the Slr1/slr1, Gid1/gid1 and Gid2/gid2 loci. Each of the F2 populations was grown in a greenhouse, evaluated for plant and leaf morphologies, flowering time, and seed dormancy by germination testing. Large variations for the morphological, flowering and germination traits were detected in each of the three F2 populations and quantitative genetic analyses for the traits were completed. We are genotyping the populations for the dormancy and GA genes using the gene-based markers. The phenotypic and genotyping data will be used to partition the phenotypic variation in seed dormancy in main (additive and dormancy) and epistatic effects of the SD and GA genes using a two-/three-gene model. The second set of experiments were conducted to evaluate pleiotropic effects of the red pigmentation gene Rc and the purple pigmentation gene Pb on seed flavonoid chemicals, dormancy, and germination. The allelic variants of the Rc/rc and Pb/pb loci were introduced into the same genetic background to identify developmental patterns of the red and purple pigments and to model the pleiotropic effects of the two genes. Experimental data revealed that the two pigment systems differ in morphological and histological patterns during the seed development, Rc had a greater effect on seed dormancy than Pb, and both genes also involve in the regulation of germination speed. And the third sets of experiments were conducted to advance on-going project to improve the resistance to pre-harvest sprouting (PHS) and germination ability of hybrid seeds using seed dormancy genes. A total of 120 F3 or F4 lines were planted in a field, evaluated for agronomic traits, and sampled seeds to evaluate genotypic difference in the degree of seed dormancy. Elite F4 lines were selected for the next experiments. Through the Native Plant Initiative at South Dakota State University (SDState), we are raising awareness of native plant species and conducting research on patterns of smoke-induced germination, as well as other traits that improve seeding germination and survival. We have scaled up our sampling of smoke-induced germination responses with a global literature synthesis, which now includes 1256 species. To understand evolutionary patterns for this global dataset, we generated a new phylogeny and conducted Ancestral State Reconstruction analyses, tests for phylogenetic signal (D statistic for binary trait data), and tests for character correlations using evolutionary modeling approaches (e.g. BiSSE and HiSSE; binary and hidden state speciation and extinction, respectively). We find that with much improved sampling, some clades show strong evidence of clustering for this germination response (e.g. Ericaceae), while others do not (e.g. Asteraceae). In another study, we examined spatial patterns in awn development and correlation with other plant traits. We leveraged digitized herbarium records to address the invasion history and trait variation in Japenese stiltgrass (Microstegium vimineum). Awns are either present or absent in Japenese stiltgrass throughout its native and invaded ranges. We coded awn presence/absence for all georeferenced records, as well as floret length, floret width, and awn length/angle. We also conducted genomic analyses using inter-simple repeat sequencing of 51 samples from 31 populations across the US to understand colonization history of this invasion. Our results show similar patterns of awn polymorphism in the native and invaded ranges, with the awned form significantly predominating at higher latitudes and the awnless at lower latitudes. Awned forms had significantly longer florets than awnless forms. Both herbarium records and genomic data suggest initial introduction and subsequent spread of the awnless form in the southeastern US, followed by a secondary invasion and spread of the awned form stemming from eastern Pennsylvania. Population structure analyses revealed that awned and awnless forms are highly genetically distinct but with some evidence of admixture. This work elucidates a key trait (the awn) helping northern forms of Japanese stiltgrass gain a foothold in colder climates. This strong geographic pattern of awn polymorphism in Japanese stiltgrass is the only case where such a north-south, awned-awnless pattern has been documented in grasses, allowing us to hypothesize that awn-facilitated diaspore burial provides protection from freezing temperatures. We have also been mapping commercially available seed sources for prairie species used in restoration and calculating phylogenetic diversity levels for different seed mixes. This information will be used to create 480 experimental plots to assess the influence of species richness, phylogenetic diversity, and genetic diversity (i.e. seed source) on soil health and pollinators. TX (Leskovar) – This year we conducted six studies: 1) Determining the potential of plant bio-stimulants to enhance seedling growth in pepper when applied as a pre-transplant treatment in the rooting media, 2) Determining the impact of solid humic substance and LED light quality on tomato transplants, 3) Evaluating the impacts of grafting on tomato thermotolerance, 4) Investigate the influence of wild-relative tomato rootstocks on grafted tomato thermotolerance, 5) Determining the impact of bio-stimulants to enhance onion and artichoke seedling growth, stand establishment and yield, and 6) Determining the effectiveness of humic substance applications on ameliorating drought and salinity stress in spinach. Additionally, we have initiated another ongoing experiment (7) focused on improving the iron nutrition of hydroponic leafy greens cultivated at high pH.  Findings from these studies are intended to provide recommendations to small-scale growers to enhance their profits and contribute to the sustainable production of high value vegetable crops. We completed our second trial of pepper responses to transplant stage bio-stimulant amendments, in which four different bio-stimulants (two humic acids, calcium spray, Trichoderma) were applied at the seedling stage to 'Mama Mia Giallo' and 'Tenor' pepper cultivars. Root and shoot parameters were measured through destructive means. Results revealed that Novihum- (solid humic acid) treated “Mama Mia Giallo’ seedlings had higher relative root growth rate and greater leaf area compared to control plants. Overall, Novihum-treated seedlings outperformed other seedlings in most shoot and root parameters one month after seeding. The results imply that humic substance amendments can aid in seedling vigor by modulating their root and shoot growth whereas calcium spray and Trichoderma resulted in poor plant performance demonstrating their lack of beneficial effect. In addition, we are conducting a study on the use of commercial microbial bio-stimulants added to media to produce organic pepper transplants. Products containing a multiple species blend of plant growth promoting Rhizobacteria (PGPR) and other beneficial plant growth promoting microorganisms are being tested on two varieties of pepper. Early results show that a blend of PGPRs added with mycorrhizae has superior performance in producing organic pepper transplants. The seedlings are now being grown in a greenhouse with organic practices to assess post-transplant effects. Our growth chamber study identified significant benefits of solid humic substance as a soil amendment in round ‘Celebrity’ and cherry ‘Chadwick’ tomato transplants under different LED light environments (fluorescent, 10B-90R, 50B-50R, 100B). At five weeks after sowing, seedlings treated with humic substance had three to five folds higher shoot and root biomass and leaf area than the controls. This led to a significantly higher early fruit harvest of ‘Celebrity’ tomatoes in humic substance treatment plants in high tunnel, while there were no significant treatment differences in total yield of both cultivars after three months of harvesting. LED light with 50B-50R ratio enhanced leaf chlorophyll content and root growth traits, while fluorescent light had the highest leaf area among the light treatments. There were no significant LED quality effects on tomato fruit yield, but humic substance enhanced the yield of ‘Chadwick’ tomatoes in 50B-50R and 100B LED treatments. A heat stress study was conducted using ‘Maxifort’-grafted tomato seedlings in a growth chamber under a stress (38/30°C, day/night) and recovery period (26/19°C). After 14 days of heat stress, ‘Maxifort’-grafted plants had higher leaf carotenoid:chlorophyll ratio and total soluble protein content than the controls. Antioxidant enzyme activities were selectively regulated under heat stress that ‘Maxifort’-grafted plants had higher leaf ascorbate peroxidase, root superoxide dismutase and catalase, although the beneficial traits did not lead to a significant alleviation of heat stress. We examined the use of tomato wild relative rootstocks (S. pennellii, S. peruvianum) to enhance the thermotolerance of tomato plants in a growth chamber. The grafted seedlings were exposed to heat stress (38/30°C) for 21 days and compared with self-grafted and ‘Maxifort’-grafted plants. Seedlings grafted onto S. peruvianum showed tolerant heat responses with higher enzymatic and non-enzymatic antioxidant capacity compared to other rootstock treatments. On the other hand, S. pennellii-grafted plants showed susceptible antioxidant enzyme activities under heat stress. Both wild relative rootstock groups had higher leaf chlorophyll content, chlorophyll fluorescence and net photosynthetic rate under heat treatment than self-grafted and ‘Maxifort’-grafted plants, but the low graft compatibility between wild rootstock and cultivated scions led to their poor plant biomass. Our team has begun a new project investigating the capability of a broad suite of plant bio-stimulants to improve the transplant growth and mature yield of onions and artichokes. In our initial experiment, we applied manufacturer recommended rates of a beneficial bacterial powder, mycorrhizal powder, combined bacterial and mycorrhizal powder, seaweed extract, and humic substance as soil amendments prior to seeding artichokes (’17-111’ and ’17-169’) and onions (‘Cirrus’, ‘Don Victor’, ‘Sofire’) in cell trays. One month after seeding, we photographed trays to quantify transplant stand heights and to estimate total emergence. Additionally, we have taken seedling samples for leaf area, leaf SPAD, root system physical parameters, and plant dry weight measurements. While this analysis is ongoing, we have observed visual differences, such as improved growth of transplants treated with the seaweed extract and humic substance, and improved emergence in artichoke trays treated with the combined microbial-mycorrhizal powder. We plan to transplant the remaining seedlings into the field at Uvalde, TX where we will cultivate them under standard management conditions and assess their changes in growth and eventual marketable yield, to assess any carryover effects of the pre-seeding applications. Seeding stage bio-stimulant applications are uncommon for onion and artichoke producers; by demonstrating the potential for improved growth and yield from use of these bio-stimulants we hope to improve the productivity and profitability of these crops. Lastly, we have initiated a new, ongoing study examining the leafy green response to different chemical forms of iron fertilizers when cultivated under high pH conditions. Iron deficiency resulting from high pH is a major challenge in hydroponics production, and its prevention at the post-transplant seedling stage is crucial to maximizing production. When iron is added in its cationic form, it reacts with various anions, forming insoluble compounds which are unavailable to crops. Iron chelates are frequently used to supply iron to crops as the chelates surround the iron ions making them stable in solution by preventing their reaction with anions. However, chelates are often unstable under high pH, necessitating their screening for suitability for high pH conditions. Our new study aimed to investigate the effectiveness of three synthetic chelators and fulvic acid, a plant biostimulant with chelating ability, on iron bioavailability for lettuce and kale grown in NFT and deep-water hydroponics under high pH conditions. Drought and salinity are two major abiotic stresses restraining crop growth and productivity worldwide, and the area affected by these two stresses is increasing. Using a gravimetric platform (Droughtspotter, Phenospex, Netherlands), we examined how humic substance improves spinach's (‘Seaside’) tolerance to the combined abiotic stresses right after transplant. Plants were exposed to either weekly applications of saline solution, restrained irrigation, a combination of the two or exposed to no stress conditions. Additionally, plants were either treated with a 1% v/v solid humic substance soil amendment or none at all.  Irrigation as automatically performed by the gravimetric platform, which also logged the amount of irrigation applied and individual pot weights every 10 minutes. Plants were harvested after one month of growth and measured for physical dimensions and nutrient contents. Initial analysis of the water use data obtained from the gravimetric platform and plant weights demonstrated that humic substance treatments induced greater water use in spinach but improved their water use efficiency. Overall, humic substances improved spinach growth and water use efficiency, subsequently enhancing their abiotic stress tolerance. VA (Welbaum) – Virginia Tech MS student, Austin King completed a project studying halophyte establishment by transplanting or direct seeding as a strategy to remediate roadway deicing salt runoff into adjacent ecosystems, 2) In collaboration with colleague Bingyu Zhao at Virginia Tech, we demonstrated that virus-induced gene silencing can be used as a tool for studying gene-for-gene pathogenicity/resistance of bacterial fruit blotch disease of cucurbits, 3) Virginia Tech Intellectual properties has patented our natural chemical seed treatment that can kill cultures of the international disease Acidovorax citrulli and on artificially inoculated seeds, 4) Virginia Tech MS student, Michael Beall, studied seed germination of the invasive grass species, Arthraxon hispidus, which can rapidly colonize new areas because it does not exhibit seed dormancy and germinates quickly (<36 hours at 30℃) over a range of conditions. Its thick vegetative ground cover decreases competition and prolific seed development aids establishment.  To further its invasive advantage, germination occurs across a range of salinities. This trait may promote recruitment into salt-stressed environments such as roadsides and tidal ecosystems. Mechanical control may be effective for controlling A. hispidus. Since seed bank longevity seems unlikely. Mowing before seed maturity will reduce abundance in the subsequent seasons. Evidence is mounting that this species has potential to become a globally pervasive non-indigenous species. With new populations of A. hispidus observed each year, it is seemingly only a matter of time before it spreads across the US and Canada, 5) Xiaoying Li has continued her Ph.D. research on edamame seed quality and seedling disease resistance. Seeds of grain and edamame soybeans were produced in the same field, processed, and stored under the same conditions before germination performance was compared. The optimal temperature range for edamame seedling emergence was 25-32℃, lower than grain-type soybean cultivars (29-36℃). Edamame soybean did not emerge at below 4℃ its apparent base temperature but may have higher tolerance to lower temperatures than grain soybean genotypes. Disease screening is produced promising lines resistant to Rhizoctonia spp.

Publications

Ali MF, Brown P, Thomas J, Salmeron M, Kawashima T. 2022. Effect of shading and pod competition during early soybean seed development. Plant Reproduction 35:179-188 <a href="https://link.springer.com/article/10.1007/s00497-022-00439-2">https://link.springer.com/article/10.1007/s00497-022-00439-2</a> Barrett CF, Huebner CD, Bender ZA, Budinsky TA, Corbett CW, Latvis M, McCain MR, Motley M, Skibicki SV, Thixton HL, Santee MV, Cumberledge AN. 2022. Digitized collections elucidate invasion history and patterns of awn polymorphism in Microstegium vimineum. American Journal of Botany 109(5): 689-705. Bolt B, Baloh A, Magnani R, Nosarzewski M, Rodriguez López CM, Geneve RL. 2022. Clipping and gibberellin treatments promote germination in dormant grape seeds. HortTechnology accepted Campbell-Martínez G, Thetford M, Wilson SB, Steppe C, Pérez HE, Miller D. 2021. Germination of coastalplain honeycombhead (Balduina angustifolia) in response to photoperiod, temperature, and gibberellic acid. Seed Science and Technology. 49:278-303. Geneve RL, Janes EW, Kester ST, Hildebrand DF, Davis D. 2022. Temperature limits for seed germination in industrial hemp (Cannabis sativa L.). Crops 2:415–427. <a href="https://doi.org/10.3390/crops2040029">https://doi.org/10.3390/crops2040029</a> Dean AN, Wigg K, Zambiazzi EV, Christian EJ, Goggi AS, Schwarte A, Johnson J, Cabrera E. 2022. Migration of oil bodies in embryo cells during acquisition of desiccation tolerance in chemically defoliated corn (Zea mays L.) seed production fields. In A. Taylor (Ed.), Modern seed technology, special issue. Agriculture, 11(2), 129. <a href="https://doi.org/10.3390/agriculture11020129">https://doi.org/10.3390/agriculture11020129</a>. Fleming M, Miller T, Fu W, Li Z, Gasic K, Saski C. 2022. Ppe.XapF: High throughput KASP assays to identify fruit response to Xanthamonas arboricola pv. Pruni (XaP) in peach. PLoS One 17 e0264543. https://<a href="https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1371%2Fjournal.pone.0264543&data=05%7C01%7Cheperez%40ufl.edu%7C8a8314b39ecf4084d36c08dadc626266%7C0d4da0f84a314d76ace60a62331e1b84%7C0%7C0%7C638064613505972793%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=lPP3XUSFCIQEdftzwTk37asANbQWZ2lXQyX8UAL5ExY%3D&reserved=0">doi.org/10.1371/journal.pone.0264543</a> Genna NG, Pérez HE. 2021. Intra-population seed survival during burial on a mass basis. Flora 274: 151756. DOI: <a href="https://doi.org/10.1016/j.flora.2020.151756">https://doi.org/10.1016/j.flora.2020.151756</a>. Gu X-Y. 2022. Seed dormancy genes and their associated adaptive traits underlie weed persistence: A case study of weedy rice. In: Persistence Strategies of Weeds in Agriculture edited by Upadhyaya, MK, Clements DR and Shrestha A. Wiley, NY. First published on February 25, 2022; https://doi.org/10.1002/9781119525622.ch4. Kimmelshue C, Goggi AS, Moore K. 2022. Single plant grain yield in corn (Zea mays L.) based on emergence date, seed size, sowing depth, and plant to plant distance. Crops 2, 62–86. <a href="https://doi.org/10.3390/crops2010006">https://doi.org/10.3390/crops2010006</a> Kimmelshue C, Goggi AS, Moore KJ. 2022. Seed Size, Planting Depth, and a Perennial Groundcover System Effect on Corn Emergence and Grain Yield. Agronomy 12(2), 437. <a href="https://doi.org/10.3390/agronomy12020437">https://doi.org/10.3390/agronomy12020437</a> Li X, Yin Y, Strawn L, Rideout S, Kuhar T, Welbaum G, Li S, Liu K, Weckworth K, Zhang B. 2022. Edamame in Virginia I. Products and Marketing. Virginia Coop. Ext. Li X, Rideout S, Strawn L, Welbaum G, Kuhar T, Li, S, Chen P, Reiter M, Zhang, B. 2022. Edamame in Virginia II. Producing a High-Quality Product. Virginia Coop. Ex. Li X, Strawn L, Huang H, Yin Y, Rideout S, Welbaum G, Duncan S, Mille R, Li S, Zhang, B. 2022. Edamame in Virginia III. Handling and Processing from Harvest to Package. Virginia Coop. Ext. Li X, Welbaum G, Rideout SL, Singer W, Zhang B. 2022. Vegetable soybean and its seedling emergence in the United States, In: Legume Crops-Prospects, Production and Uses. IntechOpen. doi: 10.5772/intechopen.102622. Marzol E, Borassi C, Carignani Sardoy M, Ranocha P, Aptekmann AA, Bringas M, et al. Fleming M, et al., Estevez J. 2022. Class III peroxidases PRX01, PRX44, and PRX73 control root hair growth in Arabidopsis thaliana. International Journal of Molecular Sciences 23: 5375 <a href="https://doi.org/10.3390/ijms23105375">https://doi.org/10.3390/ijms23105375</a>. Mayton H, Amirkhani M, Loos M, Johnson B, Fike J, Johnson C, Myers K, Starr J, Bergstrom GC, Taylor A. 2022. Evaluation of Industrial Hemp Seed Treatments for Management of Damping-Off for Enhanced Stand Establishment. Agriculture 2022, 12, 591. <a href="https://doi.org/10.3390/agriculture12050591">https://doi.org/10.3390/agriculture12050591</a> Nishiyama E, Nonogaki M, Yamazaki S, Nonogaki H, Ohshima K. 2021. Ancient and recent gene duplications as evolutionary drivers of the seed maturation regulators DELAY OF GERMINATION1 family genes. New Phytologist 230, 889-901. Nguyen CD, Chen J, Clark D, Pérez H, Huo H. 2021. Effects of maternal environment on seed germination and seedling vigor of Petunia x hybrida under different abiotic stresses. Plants 10(3): 581. DOI: <a href="https://doi.org/10.3390/plants10030581">https://doi.org/10.3390/plants10030581</a> Obregon D, Pederson G, Taylor A, Poveda K. 2022. The pest control and pollinator protection dilemma: The case of thiamethoxam prophylactic applications in squash crops. PLoS One 17(5): e0267984.  <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0267984">https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0267984</a> Shin JM, Kawashima T. 2022. Live-cell imaging reveals the cellular dynamics in seed development. Plant Science 325:111485 <a href="https://www.sciencedirect.com/science/article/pii/S0168945222003107">https://www.sciencedirect.com/science/article/pii/S0168945222003107</a> Tan JW, Kester ST, Su K, Hildebrand DF, Geneve RL. 2022. Seed priming and pericarp removal improve germination in low-germinating seed lots of industrial hemp. Crops 2:407–414. <a href="https://doi.org/10.3390/crops2040028">https://doi.org/10.3390/crops2040028</a> Taylor A, Jiang Y, Amirkhani M, Lewis E, Sosnoskie L. 2022. Imaging of Fluorescent, Systemic Seed Treatment Tracers in Hemp for the Development of a Weed Management System. Bajwa DS and Berti MT (eds.) 2022. Integrating technology with industrial crops and their products for a sustainable bioeconomy. 33rd Annual Meeting of the Association for the Advancement of Industrial Crops (AAIC). Program and Abstracts. October 9-12, 2022, Bozeman, MT, USA. Tetreault H, Fleming M, Hill L, Dorr E, Yeater K, Richards C, Walters C. 2022. A power analysis for detecting aging of dry-stored soybean seeds: Germination vs. RNA integrity assessments. Crop Science  <a href="https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1002%2Fcsc2.20821&data=05%7C01%7Cheperez%40ufl.edu%7C8a8314b39ecf4084d36c08dadc626266%7C0d4da0f84a314d76ace60a62331e1b84%7C0%7C0%7C638064613505972793%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=YBFt2d%2BHhwmT279RpShHBf9b6%2FAEPJzog5RPdimWIes%3D&reserved=0">https://doi.org/10.1002/csc2.20821</a>. Wu H, Li G, Zhan J, Zhang S, Beall BD, Yadegari R, Becraft, PW. 2022 Rearrangement with the nkd2 promoter contributed to allelic diversity of the r1 gene in maize (Zea mays). The Plant Journal 111:1701-1716. doi: 10.1111/tpj.15918. Zhou D, Barney JN, Welbaum GE. 2022. Production, Composition, and Ecological Function of Sweet-Basil-Seed Mucilage during Hydration. Horticulturae 8, no. 4: 327. <a href="https://doi.org/10.3390/horticulturae8040327">https://doi.org/10.3390/horticulturae8040327</a>

Impact Statements

VA (Welbaum) – Acidovorax citrulli is one of the most serious seed transmitted plant diseases in the world. Seed companies have zero-tolerance for seed lots infected with A. citrulli. We have made progress in the search for genetic resistance to this serious worldwide disease. Our novel seed treatment using natural chemicals offers hope for recovering infected seed lots and stopping infestation of new production fields, 2) controlling invasive species is a key to maintaining biological diversity. Understanding strategies the invasive plant Arthraxon hispidus uses to colonize new areas will lead to effective control measures such as early mowing to prevent seeding. This research will help control movement of Arthraxon hispidus areas outside the mid-Atlantic region, 3) vegetable soybeans are a nutritious and popular around the world but underutilized in the US. Most of the edamame currently consumed in the US are imported. Solving problems with poor emergence will help increase domestic production. Developing new treatments to protect seeds and seedling from diseases as well as genetic resistance to Rhizoctonia spp. fungi will help growers successfully product edamame in the US.

Date of Annual Report: 12/05/2023

Report Information

Annual Meeting Dates: 10/05/2023 - 10/07/2023
Period the Report Covers: 10/01/2022 - 09/30/2023

Participants

Participants Attachment:

W4168 Participants.docx

Brief Summary of Minutes

Minutes Attachment:

W4168 Meeting Minutes.docx

Accomplishments

OR (Elias): Oregon State University (OSU) conducts studies in both basic and applied research, the two broad objectives of the current W4168 project. We focused on the application of new technologies to assess and manipulate traits to enhance seed quality. <h4>The seed group at OSU lost two out of its three members, Dr. Hiro Nonogaki for retirement and Dr. Thomas Chastain for becoming the head of the department (100% administration position), only Dr. Sabry Elias  is currently conducting seed research. The following projects have been concluded in 2022/2023, with the publications cited below:</h4> <ol> <li>     Development of a quantitative DNA test to distinguish between annual and perennial ryegrass.</li> <li>     Evaluation of bioassay methods to screen winter wheat for quizalofop herbicide tolerance.</li> <li>     Diverse Eastern Gamagrass ecotypes: General characteristics, ploidy levels, and biogeography.</li> <li>     Effects of different storage conditions on seed quality of hemp (Cannabis sativa).</li> <li>     Production of Native Seeds (Video): Supplying Restoration (2023). It is a nine-part video series that explores the native seed supply chain in the western United States. (Video 7 Seed Testing and Certification by Oregon State University Seed Lab). Produced by Holden Films, Colorado, USA. brady@holdenfilms.org. </li> <li>     Green synthesis of copper nanoparticles extracted from guar seedling under Cu heavy‑metal stress by Trichoderma harzianum.</li> </ol> KY (Geneve, Downie, Kawashima): (Geneve) Grape seeds showed physiological dormancy and germinated at approximately 60% after 60 days of chilling stratification. Seeds cut at the distal seed end or intact seeds treated with gibberellic acid (GA) germinated at approximately 20% after 30 days. Cut seeds treated with GA at 5,000 mg·L-1  had the highest germination percentages between 63% to 83%. Results from this study provide a system that reduces the need for chilling stratification for grape seed germination by using partial seed coat removal and GA treatment. (Downie) LATE EMBRYOGENESIS ABUNDANT PROTEINs (LEAPs), intrinsically disordered proteins found in most organisms that can withstand desiccation at some stage of their life-cycle) are hypothesized to provide protection to stressed cells. So too are non-reducing sugars (NRS; trehalose, sucrose, raffinose) thought to provide desiccation tolerance. Together, these molecules are components of the natural protection and repair (NPR) mechanism in orthodox seeds, the focus of our studies. We found that the means by which plant material was prepared before sugar extraction had a non-trivial influence on the sugar profile retrieved from the tissue. Based on our results we highly recommend avoiding freeze-drying tissue prior to sugar extraction (Dirk, Zhao et al. 2023). Accurate sugar extraction techniques allowed us to demonstrate a role for raffinose in retaining water in stressed maize leaves, helping to avoid wilting during drought (Liu, Li et al. 2023). Using two orthologous dehydrin LEAPs, one from Arabidopsis (At2G21490; LEA14; (Hundertmark and Hincha 2008)), its soybean (Glycine max) orthologous protein (GmPM12; Glyma.04G009900.1) we have demonstrated their interaction with ABSCISIC ACID INSENSITIVE3 (ABI3; At3g24650). In this endeavor we were ability assisted by Ms. Deepshikha Sai Bassetti, a recent graduate (Summa Cum Laude) of the University of Kentucky Agricultural and Medical Biotechnology (ABT) program who graduated in May, 2023. Ms. Bassetti pursued her ABT research proposal in my lab throughout 2022-2023. Ms. Bassetti expressed and purified both LEAPs (LEA14 and GmPM12) and the transcription factor, ABI3. She and I ran experiments using Temperature Related Intensity Change (TRIC) to assess the binding between the dehydrin proteins, LEA14, GmPM12 and ABI3 mentioned previously. She presented her results on Thursday, April 29, 2021 1:30 PM entitled, “LEA14 and ABI3 effects on the completion of seed germination.” For which she was judged as joint winner of the Glenn B. Collins Research Award for excellence in research. I was the recipient of a grant from the University of Kentucky Office of the Vice President for Research for $80,000 to upgrade the Dianthus (NanoTemper Inc., Munich, Germany) used for TRIC assays to now also include Isothermal Spectral Shift (ISS) assays also used for molecular interactions. The instrument was sent to Germany for the upgrade and arrived safely back to my lab September 15th, 2023. Once it was reinstalled, hands-on training of 12 individuals from 12 different labs across 5 Departments, 3 Colleges and two universities was conducted on the use and capacities of the Dianthus with both TRIC and ISS (September 21st, 2023). These individuals are now capable and able to use the Dianthus for their various projects. Importantly, the new ISS capacities are a more robust, and independent, measurement of molecular interaction that is directly applicable to our efforts to demonstrate LEAP client protein interactions, with or without NRS and with or without osmotic or ionic perturbations. We have continued to work to sonoporate protective LEAPs and NRS into Drosophila melanogaster (fruit fly) embryos to enable their successful cryopreservation. Sonoporation is successful in introducing sugars into embryos but only if the latter are dechorionated and dewaxed. The dewaxing step, in particular, is detrimental to fly survival we have found, with approximately 80% mortality during this step. Attempts to sonoporate dechorionated but not dewaxed embryos were not successful. Attempts to identify the causal agent for the high mortality has not been fruitful. However, we noted that those flies expressing a recombinant LEA6 protein from Artemia franciscana (brine shrimp) survive dewaxing better than non-transformed, or flies expressing other brine shrimp, LEAs (unpublished). We are pursuing the cryopreservation of these fruit fly embryos, despite the poor pretreatment survival, as the removal of the chorion and waxy layer are essential to successful sonoporation of naturally occurring, cryoprotective molecules, to quantities sufficient to permit the formation of a glassy state within the embryos. Glass formation is seen as a requirement for survival of both cryopreservation and desiccation. This project supports our efforts to understand LEAP and NRS activities in preserving life in the desiccated cell. If successful, we will have demonstrated that it is possible to create a desiccation tolerant organism by recapitulating within it, aspects of the NPRM. (Kawashima) The endosperm within a seed is a tissue that supports embryo development and is a product of fertilization. Endosperm cells undergo nuclear divisions without cytokinesis right after fertilization, generating a large multi-nuclear cell. Cellularization subsequently occurs. The duration of this multi-nuclear endosperm phase is correlated with the final seed size. However, the molecular mechanisms and cellular dynamics by which the endosperm contributes to final seed size remains largely unknown. The Kawashima lab has characterized nuclear divisions and movement as well as the role of the cytoskeleton in this unique endosperm development in Arabidopsis thaliana via confocal live-cell imaging technology Both microtubules (MT) and actin filaments (F-actin) generate aster-shaped structure around each nucleus. While MT promotes movement of nuclei at mitosis, F-actin restricts further movement, controlling equidistance of multi nuclei in the endosperm. Furthermore, manipulations of F-actin dynamcis specifically in the endosperm cause changes in seed sizes, providing insights into a new seed size control mechanims. Using soybean as a crop model, the Kawashima lab investigated what are the differences if any early pahse seed development among cultivars with different seed sizes. Four cultivars (two with small seeds and the other two with large seeds) were grown in a green house and early seed development process were intensively investigated. We found that large-seeded cultivars have longer duration of the early phase of seed development. This results in the increased number of the cotyledon cells, thus pre-determining the max potential of the seed size. FL (Pérez): We partnered with a group of small-scale farmers interested in developing seed production systems for selected high-value vegetable and wildflower crops. This collaborative research led to assessment of the developmental physiology for selected crops resulting in identification of minimum harvest windows to ensure high-seed quality. For example, in the warm, humid southeastern region of north Florida, seeds of C. moshata ‘Bellevue Butternut’ display appropriate traits for harvest at 50 days after flowering. Brassica rapa ‘Yukina Savoy’ plants planted in the late fall produce high quality seeds by 45 days after flowering. Similarly, V. unguiculata ‘Purple Hull’ seeds should be harvested no earlier than 35 days after flowering. Seed fill of Asclepias tuberosa was high but germination was highly variable (25-80%). In another study, we investigated the efficacy of scalable, cost-effective desiccant-based drying systems to store seeds of the same crops species. Seeds of all the vegetable crops benefited from drying in the desiccant-based systems and did not display reduced germination capacity or vigor following storage. Dry storage of A. tuberosa seeds under these conditions may be limited to 9 months. However, more studies with fresh seeds are required to verify. A third project involved assessing the influence of ecotype, prescribed burn timing, and other environmental correlates with seed quality of Aristida stricta (wiregrass). Ecotype and burn month had little comparative effects on germination capacity (range 55-60%). However, exposing seeds to low winter temperatures reduced final germination. The effect of temperature on germination decrease was moderate. Unlike germination, the proportion of filled seeds was strongly influenced by ecotype and burn month. For instance, the odds of plants growing in mesic sites producing filled seeds was three times greater than for plants from xeric sites. Likewise, June appeared optimal for prescribed fire. The odds of a filled seed for plants burned in June was 18% and 8% higher than for plants burned in May or July, respectively. At the same time, for each 10 mm increase in precipitation two months before fires occurred, the odds of seed fill increased by 1%. Moreover, for each 10 mm increase in precipitation during the seed development program the odds of seed fill increased by 6%. IA (Goggi): Investigation continues into agricultural systems that protect soil and water quality, such as perennial ground covers, often stress seed from cash crops. The emergence, plant development and yield are negatively affected because cash-crop competes with the cover crop.  We seek seed characteristics that allow the cash crop to out-compete the perennial ground cover are essential for the success of these systems. We continue investigating the  effects of seed characteristics on yield at the whole-plot and single-plant level in corn based on emergence date based on plant-to-plant competition.  TX (Leskovar): This year we summarized two studies conducted previously on the role of humic substances (HS) applied to the growing media on growth and physiology of ‘Micro-Tom’ young tomato plants and ‘Celebrity’.  In the first study we found three significant results:  1) HS increased seedling root development which in turn increased water and nutrient status; 2) HS decreased oxidative stress and cell membrane damage, a response that was related to an increase in ABA and not on antioxidant enzymes SOD and CAT; and 3) HS increase yield, possibly due to improved resource use uptake. Taken together, these results indicate that humic substances helped tomato pants overcome abiotic stresses. In the second study, we found that when HS are applied to the growing media on seedlings exposed to a combination of LED light with a spectral ratio of 10% Blue-90% Red, they had a significant growth improvement that was translated into higher early yield.  MT (Torrion): In the current year, we conducted a second-year verification study on various irrigation supplementation timings during the seed development of two market classes in winter wheat (soft whites and hard reds genetics). We’ve confirmed that irrigation supplementation during the seed formation leads to late amylase activity. In the same manner, late occurrences of rainfall events (using the center pivot simulation of rain) also lead to more amylase activity. And, irrigation supplementation on top of the rainfall events even more exacerbates amylase activity in the grain. This is more concerning in soft white market class compared with the hard reds market class.  MI (Fleming): Soil seed banks: MSU’s Baker Woodlot is a protected old growth forest. Periodic floristic surveys in Baker Woodlot have documented the loss of many native species along with increased abundance of invasive species. Soil cores have been collected from nearly 200 sites within Baker Woodlot. They will be examined for the presence and viability of any of the lost native species. Desiccation tolerance: Seeds of the model plant Arabidopsis thaliana were confirmed to become capable of germinating 10 days after flowering and to acquire desiccation tolerance 14 days after flowering. Seeds at the distal end of a silique mature and acquire desiccation tolerance more quickly than seeds at the basal end, which complicates interpretation of assays done on seeds pooled across several siliques. Desiccation-sensitive seeds are able to survive desiccation if they are dried slowly over several days, but it is unclear whether this is because of a change to their desiccation tolerance mechanisms or because the normal desiccation tolerance pathways have time to be expressed. We are also using wild pea, Pisum elatius, as a complementary system to study desiccation tolerance. Seeds are mature and desiccation sensitive by 21 days after flowering, and become desiccation tolerant 24 days after flowering, when maturation drying starts. Pea seeds have physical dormancy imposed by the seed coat, and the interactions between flower color, seed coat color, dormancy, and desiccation tolerance will be explored further. We are making protoplasts from spinach and Arabidopsis leaf tissue to do pilot studies using MSU’s Flow Cytometry core facilities, which can sort protoplasts based on size, shape, and other features. We plan to make protoplasts from pea seeds and use flow cytometry to characterize their recovery or death after desiccation and rehydration. Soybean germination: Michigan farmers are planting soybeans early, at the end of April, because the increased variability in spring weather has made extending the planting season desirable. However, soybeans planted that early are vulnerable to imbibitional chilling injury as well as opportunistic fungal and insect damage. We have shown that prehydrating seeds by moving them to a 100% relative humidity environment at room temperature for 8-48 hours improves germination performance, and prehydrating for 24 hours followed by hydropriming in room temperature water for 18 hours significantly improves germination at 4 C.  Seed longevity: The RNA Integrity Number (RIN) is a good metric for seed quality. We are working to develop an alternate method as the equipment required for determining RIN is nearing obsolescence. We have shown that digital PCR can quantify integrity of a single mRNA, where degradation of that mRNA was previously linked to lower RNA integrity. The Verbascum blattaria genome is complete and the report is being prepared for publication.  CA (Khanday): Dr. Khanday has just joined this group and there is no report on accomplishment. SD (Latvis): In August 2023, Dr. Latvis moved her lab to the University of Arkansas to serve as the director of the UARK herbarium and assistant professor in the Biological Sciences department. She is a co-PI on a USDA-NRCS grant based in South Dakota to investigate the influence of phylogenetic diversity and seed sourcing on pollinator and soil health and continues to make progress on that project. In Fall 2022, we sourced seed for 107 commercially available perennial species native to the Northern Great Plains that had 3 different geographical origins. The seeds were used to create 480 experimental plots at the Oak Lake Field Station near White, SD, varying levels of species richness (8, 16, 32, and 64 species), phylogenetic diversity, and seed source (1 seed origin vs a mixture of 3 different geographic origins). Plots were established in Spring 2023 and maintained throughout the summer. During the process of mapping sources of commercially available restoration seed, we identified important geographic gaps in native seed collection, which influences combination and climate forecasting strategies. We are working on a collaborative manuscript on the gaps in the native seed market. NY (Taylor): To increase biodiversity and enhance ecosystem services with minimal loss of crop production area, farmers can plant desirable non-crop species near crop fields. Adoption of this practice is limited by inefficiencies in existing establishment methods. We have developed a novel seed-molding method allowing non-crop species to be planted with a conventional corn (Zea mays L.) planter, reducing labor and capital costs associated with native species establishment. Common milkweed (Asclepias syriaca L.) was selected as a model native species, because Asclepias plants are the sole food source for monarch butterfly (Danaus plexippus L.) larvae. Stratified A. syriaca seeds were added to a mixture of binder (maltodextrin) and filler (diatomaceous earth and wood flour) materials in a 3D-printed mold with the dimensions of a corn seed. The resulting Multi-Seed Zea Pellets (MSZP), shaped like corn seeds, were tested against non-pelleted A. syriaca seeds in several indoor and outdoor pot experiments. Molding into MSZP did not affect percent emergence or time to emergence from a 2-cm planting depth. Intraspecific competition among seedlings that emerged from an MSZP did not differ from competition among seedlings that emerged from a cluster of non-pelleted seeds. These findings demonstrate the potential of MSZP technology as a precise and efficient method for increasing agroecosystem biodiversity.  SD (Gu): Research projects on seed dormancy, germination and soil seedbank longevity in rice were advanced in the past year. Three sets of experiments were continued for genetic and molecular characterizations of interactions between the gibberellin (GA) signaling genes (Slr1, Gid1 and Gid2) and natural genes for seed dormancy. In the first set of three experiments, several thousand of seeds from single plants that are heterozygous only for each of the mutant alleles slr1, gid1 and gid2 were evaluated for the imbibition times (h) to germination under controlled conditions and genotyped for the alleles. Genic (additive and dominance) effects for each of the three loci were evaluated using a quantitative genetic model. In the second set of experiments, three F2 populations, each segregating for five loci (one for each of the GA signaling genes and four seed dormancy genes), were evaluated for the degree of seed dormancy by standard germination testing and genotyped for the five loci. The germination and genotyping data were used for QTL analysis to evaluate for interactions between the GA signaling and seed dormancy genes. The third experiment was a transcriptomic analysis to identify genes regulated by Slr1/slr1 in the embryo tissue of germinating seeds. Transcript abundance was quantified by RNA-sequencing and data analysis is underway.  Two experiments were conducted to identify the genetic basis of soil seedbank longevity in weedy rice. In the first experiment, a population of >400 recombinant inbred lines were evaluated for the survival parameters of seed samples buried in a rice field at 2 or 20 cm deep for 7 months; and the lines were genotyped with an SNP array. Mapping of QTLs for seedbank longevity was completed and modeling of the QTL G-by-E interaction is ongoing. The second experiment was conducted to evaluate all the nine genotypes at two seed dormancy QTLs for soil seedbank longevity in a total of three years. Field experiments were completed for seed samples buried in a rice field for years one and two, and the experiment for year three is ongoing.   VA (Welbaum): A new book Vegetable Seeds Production and Technology was completed for the publisher CAB International in hardcover, softcover, and ebook formats.  The book has 17 chapters.  The first six provide general information on the importance of seeds, plant reproductive biology, genetic improvement strategies, seed quality, post-harvest enhancement treatments, and organic seed production.  The remaining 11 chapters describe seed production of major world vegetable crops by family. In collaboration with Dr. Bingyu Zhao also at Virginia Tech, we continue to optimize the ALSV-based virus induced gene silencing (VIGS) system and silence immunity related genes in watermelon and melon as a tool to study host resistance to the seed transmitted disease of cucurbits Acidovarax citrulli. We have found that the needle pin pricking method reproducibly triggers strong PDS gene silencing in different watermelon and melon cultivars. We continue to  generate watermelon and melon DMR6 mutant plants via CRISPR/Cas9-mediated gene editing approach. The mutant plants are being evaluated for improved disease resistance to Acidovarax citrulli.  Virginia Tech Intellectual Properties has applied for an international patent to treat seeds with green tea or its constituents: epigallocatechin-3 gallate, catechin, epicatechin as an organic treatment to prevent bacterial infection of seeds.  AZ (Yadegari): Research was focused primarily on understanding how mutations that alter basal endosperm transfer layer (BETL) can alter endosperm development and consequently the overall kernel size and quality in maize (Zea mays). We have further analyzed single-mutant and double-mutant combinations in a class of transcription-factor (TF) genes that are responsible for proper differentiation and function of the BETL. One of the single mutants showed a reduction in kernel size and a delay in expression of genes typically associated with proper BETL development. A double-mutant combination of the same gene with a related TF gene showed a more severe phenotype and also a more severe delay/alteration of gene expression programs in BETL and the rest of the endosperm. Current analysis is focused on deciphering the gene networks associated with these mutants.

Publications

Impact Statements

AZ (Yadegari): Cereal endosperm is of enormous importance to the economy because it constitutes a major portion of human caloric intake directly or indirectly. Endosperm development involves cell proliferation and differentiation processes that are sensitive to environmental stresses including drought and heat. Drought causes major losses in crop yield globally. We know little about the role of gene regulatory programs responsible for establishment of cell fate in basal endosperm transfer layer (BETL), a cell type responsible for uptake of sugar and metabolites from the underlying maternal kernel tissues. A dissection of the encoded functions would enable a deeper understanding of the genetic and cell biological processes that underlie endosperm development.